"In this post, Alberto Martín-Martín, Enrique Orduna-Malea , Mike Thelwall, Emilio Delgado-López-Cózar, analyse the relative coverage of the three main research databases, Google Scholar, Web of Science and Scopus, finding significant divergences in the social sciences and humanities and suggest that researchers face a trade-off when using different databases: between more comprehensive, but disorderly systems and orderly, but limited systems. "
Source: London School of Economics and Political Science blog, December 3, 2019, https://blogs.lse.ac.uk/impactofsocialsciences/2019/12/03/google-scholar-web-of-science-an...
The post draws on an article published in the Journal of Infometrics:
Martín-Martín, Alberto, Enrique Orduna-Malea, Mike Thelwall, and Emilio D. López-Cózar. “Google Scholar, Web of Science, and Scopus: A Systematic Comparison of Citations in 252 Subject Categories.” Journal of Infometrics 12 no. 4 (2018): 1160-1177 and SocArXiv. doi:10.31235/osf.io/42nkm.