A bibliographic database administered by the US National Library of Medicine (NLM) that contains over 24 million references to journal articles in biomedicine, health, and related life sciences. Coverage extends to around 5200 journals, with particular emphasis on US journals, and around three-quarters of a million new records are added annually. The articles are indexed using the NLM’s Medical Subject Heading (MeSH) thesaurus, which permits searching using both alphabetical and hierarchical approaches. MEDLINE is the major component of the NLM’s PubMed database and can be accessed via Entrez.