PubMed contiene más de 25 millones de citas de la literatura biomédica de MEDLINE,revistas de ciencias biológicas, y los libros en línea. Las citas pueden incluir vínculos a contenido de texto completo de los sitios web de editores PubMed Central.
PubMed, available via the National Center for Biotechnology Information (NCBI) Entrez life sciences retrieval system, was developed at the National Library of Medicine (NLM), located at the U.S. National Institutues of Health (NIH). Entrez is the text-based search and retrieval system used at NCBI for services including PubMed, Nucleotide and Protein Sequences, Protein Structures, Complete Genomes, Taxonomy, OMIM, and many others. PubMed provides access to bibliographic information that includes MEDLINE and OLDMEDLINE.PubMed coverage also includes the following:
The out-of-scope citations (e.g., articles on plate tectonics or astrophysics) from certain MEDLINE journals, primarily general science and chemistry journals for which the life sciences articles are indexed for MEDLINE.
Citations that precede the date that a journal was selected for MEDLINE indexing.
Some additional life science journals that submit full text to PubMedCentral and receive a qualitative review by NLM