PubMed covers 5600 life science journals from 80 countries, as well as National Library of Medicine online books. Coverage runs from 1946 forward.
PubMed is produced and updated daily by the U.S. National Library of Medicine
In addition to MEDLINE citations, PubMed also contains:
The best way to search PubMed is by using the MeSH subject headings, or Medical Subject Headings. However, for a quick search, click on the Advanced Search link at the top of the PubMed homepage.