Kulkarni, A. V.; Aziz, B.; Shams, I.; Busse, J. W. Comparisons of Citations in Web of Science, Scopus, and Google Scholar for Articles Published in General Medical Journals. JAMA. 2009, 302 (10): 1092–6. PMID 19738094. doi:10.1001/jama.2009.1307.
Kulkarni, A. V.; Aziz, B.; Shams, I.; Busse, J. W. Comparisons of Citations in Web of Science, Scopus, and Google Scholar for Articles Published in General Medical Journals. JAMA. 2009, 302 (10): 1092–6. PMID 19738094. doi:10.1001/jama.2009.1307.