Comparing the coverage, recall, and precision of searches for 120 systematic reviews in Embase, MEDLINE, and Google Scholar: a prospective study
Systematic Reviews (2016) - Comments
pubmed: 26932789  doi: 10.1186/s13643-016-0215-7  issn: 2046-4053 

Wichor M. Bramer, Dean Giustini, Bianca M. R. Kramer