B – Google Scholar

Halevi G, Moed H, Bar-Ilan J. Suitability of Google Scholar as a source of scientific information and as a source of data for scientific evaluation – Review of the Literature. Journal of Informetrics 2017;11(3):823-834
(doi: 10.1016/j.joi.2017.06.005)  

The authors aimed to review some studies to provide insights into Google Scholar (GS) ability to replace controlled databases in various subject areas. Results show that GS has significantly expanded its coverage through the years which makes it a powerful database of scholarly literature. However, the quality of resources indexed and overall policy still remains known. Caution should be exercised when relying on GS for citations and metrics mainly because it can be easily manipulated and its indexing quality still remains a challenge.