PubMed



PubMed is a free search engine offered by the United States National Library of Medicine as part of the Entrez information retrieval system. The inclusion of an article in PubMed does not endorse that article's contents. The PubMed service allows searching the MEDLINE database. MEDLINE covers over 4,800 journals published in the United States and more than 70 other countries primarily from 1966 to the present. In addition to MEDLINE, PubMed also offers access to:


 * OLDMEDLINE for pre-1966 citations.
 * Citations to articles that are out-of-scope (e.g., covering plate tectonics or astrophysics) from certain MEDLINE journals, primarily general science and general chemistry journals, for which the life sciences articles are indexed for MEDLINE.
 * In-process citations which provide a record for an article before it is indexed with MeSH and added to MEDLINE or converted to out-of-scope status.
 * Citations that precede the date that a journal was selected for MEDLINE indexing (when supplied electronically by the publisher).
 * Some life science journals that submit full text to PubMed Central and may not have been recommended for inclusion in MEDLINE although they have undergone a review by NLM, and some physics journals that were part of a prototype PubMed in the early to mid-1990's.

Many PubMed citations contain links to full text articles which are freely available, often on the PubMed Central digital library.

PubMed is one of a number of search engines through which it is possible to search the MEDLINE database; the National Library of Medicine leases the MEDLINE information to a number of private vendors such as Ovid and SilverPlatter. PubMed has been available free on the Internet since the mid-1990s.

Because MEDLINE is the core component of PubMed, an understanding of MEDLINE is essential for effective searching in PubMed.