Emerging Research Themes Research Articles

Circular supply chains in manufacturing—Quo vadis? Accomplishments, challenges and future opportunities

AbstractCircular approach in manufacturing supply chain (SC) operations yields multiple benefits through optimal utilisation and consumption of resources. This study maps the scope and structure of circularity in the manufacturing SC discipline and explores the evolution of the domain over time. We review 946 journal articles published between 2013 and September 2023. Our study identifies key drivers and barriers to circular economy (CE) deployment in manufacturing SC operations, bibliometric parameters, emerging research themes, decision support tools, theories and applications. Using the theory extension approach, we propose a strategic framework to fortify the deployment of circularity in SCs. This comprehensive study renders a methodological contribution through combined descriptive content analysis and bibliometric and network analyses to evaluate the circular manufacturing SC operations concepts, theories and applications. We posit that manufacturing firms require to deploy innovation‐led approaches to embed the CE strategies in their SC operations. We find that the studies investigating green skill development and circularity‐culture adoption can facilitate manufacturers to understand the efficacy of circularity in their SC operations. The findings of this study can facilitate the practitioners to identify the links between the CE approaches and their strategic implications and examine CE implementation at the strategic level.

Traversing the Evolution of Research on Engineering Education for Sustainability: A Bibliometric Review (1991–2022)

Engineering education plays a pivotal role in cultivating the engineering capacity for sustainable development. Nonetheless, there has been no comprehensive review that examines sustainability as a distinct knowledge domain within engineering education. This review filled this gap by conducting a bibliometric review to document the research landscape, analyze the intellectual structure of the literature, and identify emerging research themes. The review sourced 2738 Scopus-indexed documents published between 1991 and 2022. Data analyses included descriptive statistics, co-citation analysis, and keyword co-occurrence analysis. The study identified consistent growth in research output and geographic diversity. Four predominant conceptual themes were identified in the literature: (1) Engineering Education Reform, (2) Engineering Competencies, Pedagogy, and Curriculum, (3) Curriculum Assessment and Benchmarks, and (4) Sustainable Technologies. Findings emphasize the need for defining precise engineering competencies related to sustainability, incorporating diverse teaching methods, and ensuring that sustainability learning outcomes align with changing industry norms, regulations, and accreditation criteria. The study also highlights a growing focus on the use of Industry 4.0 technologies as a means of achieving sustainability outcomes. The review underscores the need for sustained curriculum reform to successfully transform engineering education toward sustainability.

Knowledge mapping on the sun-induced chlorophyll fluorescence technology research: a scientometric and visualization analysis.

The sun-induced chlorophyll fluorescence (SIF) has received increasing attention over the past few years. This scientometric study analyzed the SIF research field, based on publications available in Web of Science Core Collection visualization, and cluster analysis enabled us to map the knowledge domain and intellectual landscape of this field and identify thematic trends, landmark articles, and emerging research themes. In this study, the software VOSviewer and CiteSpace were used to identify the intellectual base and research front using visualization and analysis. Then, we analyzed synthesized networks of co-authorship (author, institution, and country), co-citation (author, document, and journal), and co-occurring keywords. SIF has increased its publication output steadily since 2002. This study provided a visual knowledge map of the major research domains of SIF. Also, explanations and implications of the findings were explored, and the emerging trends were identified. This report provides a thorough overview of the current state and growth trends of SIF research, and it helps researchers and practitioners understand the major areas of attention in this area and provides insights into prospective areas for further study.

Bibliometric Analysis of the State of Research on Agroecology Adoption and Methods Used for Its Assessment

As a sustainable and holistic approach to agriculture, agroecology has received considerable attention in recent years because of its potential to address the environmental, economic, and social challenges of agricultural systems. In order to identify key trends, influential authors, impactful journals, and emerging research themes surrounding the agroecological adoption topic, we performed a bibliometric analysis based on metadata from documents dealing with the topic and methods employed for its assessment over the period of January 1990 to July 2023, extracted from the Web of Science database. Based on the metadata of more than 1280 articles, our analyses show that the “identification of agroecology adoption determinants” and the “development of knowledge for food sovereignty” are among the trendiest research topics, while farming systems management and biodiversity issues are basic themes. The issue of analyzing agricultural productivity is more often linked to the impact of climate change. Also, we find that machine learning methods are not yet widely used to model the process of farm agroecological adoption. The contribution of African countries to the topic remains marginal in terms of documents produced, despite the predominance of traditional agriculture on the continent.

A Bibliometric Analysis of Integrating Tourism Development into Urban Planning

This study conducts a literature analysis on integrating tourism development into urban planning to understand the current state of research in the field and identify potential areas for future study. The analysis, based on 11,134 articles published between 2010 and 2023, in the Scopus database, aims to identify emerging research themes, emphasize interdisciplinary collaboration, and reveal global research networks. Utilizing citation analysis, co-authorship analysis, co-occurrence analysis, bibliographic coupling analysis, and co-citation analysis with the use of VOSviewer (version 1.6.19) and Python programming language, the study sheds light on key trends in the integration of tourism development into urban planning. The findings provide a comprehensive understanding of the field’s current landscape, highlighting the importance of interdisciplinary cooperation and global research networks. This study offers valuable insights for researchers, practitioners, and policymakers, facilitating the advancement of sustainable urban tourism practices and guiding future research endeavors in integrating tourism development into urban planning.

Earnings management: a three-decade analysis and future prospects

PurposeThis paper undertakes an extensive and systematic review of the literature on earnings management (EM) over the past three decades (1992–2022). Furthermore, the study identifies emerging research themes and proposes future avenues for further investigation in the realm of EM.Design/methodology/approachFor this study, a comprehensive collection of 2,775 articles on EM published between 1992 and 2022 was extracted from the Scopus database. The author employed various tools, including Microsoft Excel, R studio, Gephi and visualization of similarities viewer, to conduct bibliometric, content, thematic and cluster analyses. Additionally, the study examined the literature across three distinct periods: prior to the enactment of the Sarbanes-Oxley Act (1992–2001), subsequent to the implementation of the Sarbanes-Oxley Act (2002–2012), and after the adoption of International Financial Reporting Standards (2013–2022) to draw more inferences and insights on EM research.FindingsThe study identifies three major themes, namely the operationalization of EM constructs, the trade-off between EM tools (accrual EM, real EM and classification shifting) and the role of corporate governance in mitigating EM in emerging markets. Existing literature in these areas presents mixed and inconclusive findings, suggesting the need for further theoretical development. Further, the study findings observe a shift in research focus over time: initially, understanding manipulation techniques, then evaluating regulatory measures, and more recently, investigating the impact of global accounting standards. Several emerging research themes (technology advancements, cross-cultural and cross-national studies, sustainability, behavioral aspects and non-financial indicators of EM) have been identified. This study subsequent analysis reveals an evolving EM landscape, with researchers from disciplines like data science, computer science and engineering applying their analytical expertise to detect EM anomalies. Furthermore, this study offers significant insights into sophisticated EM techniques such as neural networks, machine learning techniques and hidden Markov models, among others, as well as relevant theories including dynamic capabilities theory, learning curve theory, psychological contract theory and normative institutional theory. These techniques and theories demonstrate the need for further advancement in the field of EM. Lastly, the findings shed light on prominent EM journals, authors and countries.Originality/valueThis study conducts quantitative bibliometric and thematic analyses of the existing literature on EM while identifying areas that require further development to advance EM research.

Bridging the financial divide: a bibliometric analysis on the role of digital financial services within FinTech in enhancing financial inclusion and economic development

Financial technology (FinTech) and financial inclusion have become increasingly significant as means to alleviate poverty, reduce income inequality, and promote economic growth. This study presents a bibliometric analysis of research on the role of digital financial services in promoting financial access and economic development between 2010 and 2023. Using Scopus database, 695 documents were selected, and Biblioshiny and VOSviewer software were employed for analysis. The study aims to identify research themes, analyze publication trends, assess geographical distribution, recognize influential authors, institutions, and journals, uncover highly cited articles, and determine research gaps. The results reveal a growing interdisciplinary interest in FinTech and financial inclusion, with a surge in research production since 2016, emphasizing the significance of digital financial services in addressing the limitations of traditional financial institutions. The findings also highlight influential authors, institutions, and publications that have shaped the discourse, global collaboration patterns, and emerging research themes and trends. Policymakers are encouraged to foster an environment conducive to the growth and integration of FinTech, while future research directions should focus on the impact of digital financial services on vulnerable populations, alternative financing solutions, and the potential of emerging technologies in advancing financial inclusion and economic development. This analysis underscores the importance of interdisciplinary collaboration, global cooperation, and vigilance in addressing the challenges and opportunities presented by the rapid adoption of digital financial services in promoting inclusive and sustainable economic development.

Bibliometric Analysis of the Influence of Academic Research on HRM Strategy, Employee Performance, and Organizational Success Globally

This bibliometric analysis explores the profound influence of academic research on Human Resource Management (HRM) strategy, employee performance, and global organizational success. Leveraging a comprehensive dataset from reputable academic databases, the study employs bibliometric techniques to analyze patterns of publication, citation, collaboration, and keyword trends within the HRM research domain. The findings reveal a multifaceted landscape of HRM scholarship. Co-authorship network analysis identifies prolific authors and research clusters, highlighting the collaborative nature of HRM research. Citation analysis uncovers highly influential publications, showcasing the impact of seminal works on HRM theory and practice. Keyword analysis unveils emerging research themes, reflecting the field's responsiveness to evolving challenges and trends. Notably, the analysis underscores the significance of evidence-based HRM practices and the global context in which HRM operates. It recognizes the role of academic research in shaping HRM strategies that enhance employee performance and contribute to global organizational success. This study provides valuable insights for HRM practitioners, researchers, and organizational leaders by offering a comprehensive overview of the evolving HRM landscape. It emphasizes the importance of collaboration, the influence of seminal works, and the dynamic nature of HRM research. Understanding these dynamics is pivotal for advancing HRM scholarship and driving organizational excellence in a globalized world.

Redactable Distributed Ledgers: A Survey

Blockchain and distributed ledger technology started as a decentralized infrastructure to enable and manage digital currency like Bitcoin without relying on a central authority. One of the attractive features provided by blockchain technology is its append-only “immutability” feature, which means the stored data cannot be modified or manipulated by any means once it is validated in the blockchain ledger. Such immutability helps traceability, auditing, and non-repudiation, which builds decentralized trust among un-trusted parties. Despite that, immutability if misused could lead to the permanent existence of sensitive information and misinformation in the blockchain. Incidents like broadcasting illegal content have already taken their place in blockchain systems. Such incidents call for prompt solutions for mitigation. One emerging research theme, “redactable distributed ledgers” such as redactable blockchain provides approaches for modifying ledgers with certain controllability. This article aims to survey the current research landscape about redactable distributed ledgers. We will first describe the motivations behind redactable distributed ledgers. Compared to other relevant surveys, we comprehensively summarized and briefly explained the underlying technologies for supporting redactable distributed ledgers. We mainly focused on chameleon hash-based redactable blockchain structure and classifications, with detailed comparisons and illustrations. Further, we tackled new distributed ledger structures, including the new state-of-the-art block matrix structure. Furthermore, new applications that can be enabled by redactable distributed ledgers and future research directions are discussed in detail. This article emphasizes the motivation of utilizing the redactable distributed ledgers in several critical applications to mitigate misuse of immutability features threatening the original known design of distributed ledgers.

Emergence of Wisdom Research in Higher Education during 1988–2022

Purpose: This paper focuses on exploring the emerging trends and themes of wisdom research in higher education during the 1988-2022 period.Study design/methodology/approach: Wisdom publications (n=523) found in the Web of Science database were quantitatively analysed. For mapping the emerging research themes and trends we applied Bibliometric Analysis (i.e., citation, co-citation, bibliographic coupling, co-word, and co-authorship analyses). VOSviewer software was used for analysis and visualization.Findings: Findings indicated an exponential growth in wisdom publications that could provide opportunities for educational researchers for many years ahead. The main emerging themes were: pedagogy, teaching, students, intelligence, character, ethics, wisdom, local wisdom, phronesis, practical wisdom, spirituality, empathy, inequality, mindfulness, sustainability, and human capital.Originality/value: This study uses science mapping technique of Bibliometric Analysis that is still a very new method in educational research.

Exploring the Main Determinants of National Park Community Management: Evidence from Bibliometric Analysis

The establishment of protected areas such as national parks (NPs) is a key policy in response to numerous challenges such as biodiversity loss, overexploitation of natural resources, climate change, and environmental education. Globally, the number and area of NPs have steadily increased over the years, although the management models of NPs vary across different countries and regions. However, the sustainability of NPs necessitates not only effective national policy systems but also the active involvement and support of the local community and indigenous people, presenting a complex, multifaceted challenge. Although the availability of literature on community-based conservation and NPs has increased over the years, there is a lack of research analyzing trends, existing and emerging research themes, and impacts. Hence, in this study, we employed bibliometric methods to conduct a quantitative review of the scientific literature concerning community management of NPs on a global scale. By analyzing data from published articles, we identified research hotspots and trends as well as the quantity, time, and country distribution of relevant research. We developed a framework to illustrate the main research hotspot relationships relevant to NPs and community management, then summarized these findings. Based on the literature from 1989 to 2022, utilizing 2156 research papers from the Web of Science Core Collection database as the data source, visualizations were conducted using the VOSviewer software (1.6.18). Based on the results of network co-occurrence analysis, the initial focus of this field was on aspects of resource conservation. However, with the convergence of interdisciplinary approaches, attention has gradually shifted towards human societal well-being, emphasizing the “social-ecological” system. Furthermore, the current research hotspots in this field mainly revolve around issues such as “natural resources, sustainable development, stakeholder involvement, community management, sustainable tourism, and residents’ livelihoods”. Effectively addressing the interplay of interests among these research hotspot issues has become an urgent topic for current and future research efforts. This exploration necessitates finding an appropriate balance between environmental conservation, economic development, and human welfare to promote the realization of long-term goals for sustainable development in NPs.

A bibliometric analysis of situational interest research

AbstractInterest is a variable that assists students in acquiring knowledge and instructors in creating an encouraging classroom environment. Situational interest, on the other hand, is a type of interest that will assist students' interest to develop by organising environmental conditions. The research on situational interest has been ongoing for more than two decades, and the bibliometric information of this research has grown. The current research aims to examine trends and advances to assist researchers in understanding the perspective of situational interest research. The bibliometric analysis was conducted with Biblioshiny and VOSviewer. The current study analysed WoS data about the meta‐information of 573 published articles on situational interest. The results obtained from the WoS database reveal a growing interest in applying situational interest. Bradford's law results show that 195 articles published in 15 journals were in Zone 1. The result of Lotka's law explained that theoretical and observed research data fit. Education‐related keywords such as achievement, motivation, text, recall, comprehension, and other education‐related variables such as self‐efficacy and design, gender, college students, biology, and context have been placed under the basic theme that is most relevant and developing. It can be said that other results of the current study guide authors about situational interest research. Context and implicationsRationale for this studyThe studies on situational interest have increased over the last two decades, but there are few reviews of situational interest publications. This study has examined trends and advances in the studies to assist researchers in understanding the perspective of situational interest research with bibliometric analysis.Why the new findings matterThe findings have highlighted trends and advances in the scientific output of situational interest with bibliometric analysis.Implications for practitionersIn addition to revealing the trends and advances in situational interest research, the findings can help to focus more on some emerging research themes that can guide future situational interest researchers. According to findings, the recent research of situational interest focuses on cognitive load, motivation, achievement, and emerging technology such as augmented reality technology. The Four‐Phase Model of Interest Development is the most popular document among situational interest research to understand situational interest. The results show that researchers had an international collaboration from different countries and different institutions.

Mapping the Landscape of Artificial Intelligence Research: A Bibliometric Approach

This research study employs a comprehensive bibliometric approach, enhanced by the utilization of VOS viewer, to map the expansive landscape of artificial intelligence (AI) research. Through the meticulous collection, pre-processing, and analysis of a diverse dataset, this study uncovers the multifaceted dimensions that define AI research. The analysis encompasses publication trends, authorship dynamics, citation patterns, and emergent research themes. The integration of VOS viewer’s visualization capabilities enriches the exploration by offering intuitive representations of collaboration networks, citation maps, and thematic clusters. The results highlight the growth trajectory of AI research, the collaborative networks among researchers and institutions, the influence of seminal works, and the emergence of thematic trends. Moreover, the study contextualizes the findings, discussing their implications for interdisciplinary collaboration, ethical considerations, and the societal impact of AI research. Ultimately, this research contributes to a comprehensive understanding of AI research dynamics, guiding future exploration, collaboration, and innovation within this rapidly evolving domain.

Artificial intelligence as an enabler of quick and effective production repurposing: an exploratory review and future research propositions

The outbreak of Covid-19 created disruptions in manufacturing operations. One of the most serious negative impacts is the shortage of critical medical supplies. Manufacturing firms faced pressure from governments to use their manufacturing capacity to repurpose their production for meeting the critical demand for necessary products. For this purpose, recent advancements in technology and artificial intelligence (AI) could act as response solutions to conquer the threats linked with repurposing manufacturing (RM). The study’s purpose is to investigate the significance of AI in RM through a systematic literature review (SLR). This study gathered around 453 articles from the SCOPUS database in the selected research field. Structural Topic Modelling (STM) was utilised to generate emerging research themes from the selected documents on AI in RM. In addition, to study the research trends in the field of AI in RM, a bibliometric analysis was undertaken using the R-package. The findings of the study showed that there is a vast scope for research in this area as the yearly global production of articles in this field is limited. However, it is an evolving field and many research collaborations were identified. The study proposes a comprehensive research framework and propositions for future research development.

Food tourism research in India – current trends and future scope

ObjetivoEl estudio tiene como objetivo mejorar el conocimiento al ofrecer perspectivas de un mercado emergente mediante la revisión de la literatura existente sobre turismo gastronómico. Este estudio aplica un análisis de múltiples métodos, que proporciona información sobre el avance del turismo gastronómico en la India, las contribuciones, los hallazgos críticos y los temas de investigación emergentes.Diseño/metodología/enfoqueEl estudio adoptó un análisis multimétodo mediante un análisis descriptivo, narrativo y bibliométrico utilizando VOSviewer para analizar los artículos de investigación publicados sobre el turismo gastronómico en la India preseleccionados de Scopus y Google Scholar.ResultadosLa investigación futura debería centrarse en calibrar el potencial del turismo gastronómico en las distintas regiones del país, aplicando marcos teóricos que no se han utilizado. “Diversidad culinaria y patrimonio”, “Turismo gastronómico sostenible y responsable”, “Comportamiento del consumidor y experiencias de turismo gastronómico”, “Desarrollo rural e impacto económico”, “Tecnología y digitalización”, “Colaboración de las partes interesadas”, “Seguridad e higiene alimentaria”, “Política y regulación” fueron los temas de investigación futura identificados. Estos hallazgos son significativos para las economías emergentes de todo el mundo.Implicaciones teóricasEste estudio resumió el progreso de la investigación sobre turismo alimentario en la India, las contribuciones y los temas emergentes, complementando la necesidad de estudiar el turismo alimentario en la India. Este estudio contribuyó metodológicamente a la bibliografía al adoptar una revisión multimétodo que combina el análisis descriptivo, narrativo y bibliométrico. Por último, al proponer ideas y constructos para futuras investigaciones, este estudio proporciona orientaciones para futuras investigaciones sobre el turismo gastronómico desde la perspectiva de un mercado emergente.Implicaciones practicesLos resultados ayudarán a los gestores y a las partes interesadas a comprender los factores que influyen en los turistas, el marketing de los destinos y la creación de marcas, contribuyendo a una planificación y ejecución eficaces de las estrategias de turismo gastronómico para promocionar los destinos. Los temas y palabras clave identificados pueden ayudar a los académicos e investigadores a profundizar en los temas de investigación emergentes en el turismo gastronómico.Originalidad/valorSe trata del primer estudio que analiza la investigación sobre turismo gastronómico en la India adoptando un análisis multimétodo. El estudio proporciona un análisis en profundidad aplicando un análisis descriptivo, narrativo y bibliométrico, destacando las tendencias críticas y los temas de investigación. También se propone un marco para futuros estudios.

A Bibliometric Analysis of Financial Technology: Unveiling the Research Landscape

This study presents a comprehensive bibliometric analysis of research on financial technology (FinTech) as a methodology. The aim is to unveil the research landscape, trends, and influential factors within this rapidly evolving field. By examining publication records, citation patterns, and thematic maps, valuable insights into the intellectual structure and impact of FinTech research are provided. The analysis highlights the increasing research output and global interest in FinTech, identifies key contributors and knowledge hubs driving the field, and uncovers emerging research themes such as blockchain technology, digital payments, robo-advisors, peer-to-peer lending, and regulatory frameworks. This analysis serves as a roadmap for researchers, industry professionals, and policymakers, offering guidance for navigating the vast body of FinTech research, identifying research gaps, and fostering collaborations to drive innovation in the financial industry. Overall, this bibliometric analysis contributes to a better understanding of the current state of FinTech research and provides valuable insights for future research endeavors and decision-making in the field.

FinTech in small and medium enterprises (SMEs): A review and future research agenda

FinTech and SMEs are gaining attention from scholars all over the world considering their growing significance. This study explores the current dynamics in the field of FinTech with reference to SMEs. This is done by examining 104 documents identified from Scopus and Web of Science databases in a systematic manner following PRISMA protocol. The study uses an amalgamation of systematic literature review and bibliometric and content analysis in a meticulous manner to trace the research progression. It identifies the influential authors, articles, sources, organizations, and countries contributing significantly to the research domain. It also focusses on examining research trends, mature as well as emerging research themes on the basis of content analysis and thematic mapping. This paper provides significant insights about prior research conducted in the field by identifying eight research clusters It also proposes an integrated framework on the basis of extensive review of literature. The findings from the study would help scholars interested in the field to set the direction for their future studies. This study is of practical relevance for both SMEs as well as FinTech companies and also draws the attention of policy makers towards regulatory challenges.

E-Learning in College: Bibliometric Analysis of Virtual Learning Environments and Online Course Delivery

Electronic Learning, also known as e-learning, has become an integral part of modern education systems, revolutionizing traditional learning practices in higher education. This research paper presents a comprehensive bibliometric analysis of virtual learning environments (VLEs) and online course delivery in higher education. The study involves data collection from reputable academic databases, including Web of Science, Scopus, PubMed, Google Scholar, and institutional repositories. The research methodology includes co-authorship network analysis, journal and conference analysis, citation analysis, and keyword co-occurrence analysis using VOSviewer software. The analysis reveals collaborative patterns among researchers, influential publication outlets, highly cited papers, and emerging research themes in electronic learning. The results offer valuable insights into the evolution of electronic learning research, identifying key contributors, trends, and gaps in the field. This study aims to guide educators, researchers, and policymakers in enhancing electronic learning experiences and shaping the future of education in higher institutions.

Analyzing the Evolution of Auditing and Financial Insurance: Tracking Developments, Identifying Research Frontiers, and Charting the Future of Accountability and Risk Management

This research employed a bibliometric analysis to examine the evolution of financial audit and insurance, identify key developments, and determine research frontiers in the field. The analysis was conducted on a comprehensive dataset comprising scholarly articles, conference papers, and relevant publications. The data underwent preprocessing to ensure accuracy and reliability. Using VOSviewer, various analysis techniques were applied, including co-authorship analysis, citation analysis, and keyword and topic analysis. The findings revealed collaboration patterns among researchers, influential works, emerging research themes, and potential research frontiers. The results highlighted the impact of technological advancements, regulatory changes, and emerging risks on the field. The interpretation of the findings contributes to the understanding of accountability and risk management practices. The research identifies areas for further investigation, such as the integration of emerging technologies, regulatory effectiveness, and the management of emerging risks. The results provide insights into the past, present, and future trajectory of financial audit and insurance, guiding future research efforts and contributing to the advancement of accountability and risk management practices in the financial sector.

Exploring the Shift Toward Sustainable Finance and Financial Reporting: An Extensive Analysis of Emerging Trends, Research Patterns, and Implications for Global Sustainability

This study presents a comprehensive analysis of the shift toward sustainable finance and financial reporting, examining emerging trends, research patterns, and their implications for global sustainability. The research employs bibliometric analysis to explore the scholarly landscape, identify key areas of focus, and understand the interconnections within the field. The study analyzes publication output over time, identifies influential journals, authors, and institutions, and investigates citation networks. Through content analysis, it identifies emerging research themes and topics within sustainable finance and financial reporting. Additionally, the study explores the implications of sustainable finance and financial reporting for promoting global sustainability and sustainable development. The findings highlight a steady growth in research publications in the field, reflecting the increasing interest in sustainable finance and financial reporting. Key journals, authors, and institutions contributing to the field are identified, indicating the thought leadership and expertise in sustainable finance and financial reporting. Highly cited articles and influential authors shape the discourse and provide valuable references for further research.