A considerable proportion of clinicians and researchers face difficulties in identifying the available databases of biomedical information when performing literature searches for the needs of clinical practice and research. PubMed is the most commonly used database of biomedical information in the Western world. Open-access (free), full-text publications are available through PubMed Central. Currently, only a relatively small subset of the more than 17 million records on PubMed are included in PubMed Central and thus are full text, open access.
Falagas ME, Giannopoulou KP, Issaris EA, Spanos A. World Databases of Summaries of Articles in the Biomedical Fields. Arch Intern Med. 2007;167(11):1204-1206. doi:10.1001/archinte.167.11.1204