It is an important task to connect encyclopaedic knowledge graphs by finding and linking the same entity nodes. Various available automated linking solutions cannot be applied in situations where data is sparse, private or a high degree of correctness is expected. Wikidata has grown into a leading linking hub collecting entity identifiers from various registries and repositories. To get a picture of connectability, we analysed the linking methods and results between the COURAGE registry and Wikidata, VIAF, ISNI and ULAN. This paper describes our investigations and solutions while mapping and enriching entities in Wikidata. Each possible mapped pair of entities received a numeric score of reliability. Using this score-based matching method, we tried to minimise the need for human decisions, hence we introduced the term human decision window for the mappings where neither acceptance nor refusal can be made automatically and safely. Furthermore, Wikidata has been enriched with related COURAGE entities and bi-directional links between mapped persons, organisations, collections, and collection items. We also describe the findings on coverage and quality of mapping among the above mentioned authority databases.