A comprehensive electronic archive of the peer-reviewed literature relevant to the biological sciences that provides access to over 10 million citations. The PubMed search system provides access to the PubMed database of bibliographic information, which is drawn primarily from MEDLINE and PREMEDLINE. In addition, for participating journals that are indexed selectively for MEDLINE, PubMed includes all articles from that journal, not just those that are included in MEDLINE. PubMed also provides access to the molecular biology databases included in NCBI’s Entrez retrieval system.