Duplication rates (proportion of total results that are duplicates) in Google Scholar and Web of Science searches across the 7 case studies.

Duplication rates are assessed for up to 1,000 search records (or the total number where less than c. 1,300). For Web of Science the full text results were ordered by publication date (newest first) and relevance where more than 1,000 results were returned. Numbers are duplication rate (%) followed by total search records in parentheses.