Citations are useful signals of information salience, but little research has identified the patterns of information selection, transformation, and organization that they espouse. This paper investigated the summarization strategies followed in the writing of literature review sections of information science research papers. We found that the summarization strategies followed are different for the two major styles of literature review writing, descriptive versus integrative literature reviews. Descriptive literature reviews, which focus on individual descriptions of research papers, are more likely to reference the Method and the Result sections of the cited paper and copy-paste text the referenced text. In contrast, integrative literature reviews, which synthesize the main ideas for many papers together, have more critiques and focus mainly on the Conclusion sections. These findings, based on a hand-annotated dataset, have the potential to scale up into a transformation-invariant neural architecture for scientific summarization that can generate different summaries of the input text with integrative or descriptive characteristics.