PubMed (Public MEDLINE) is a free resource developed and maintained by the National Center for Biotechnology Information (NCBI) at the National Library of Medicine® (NLM). PubMed gives free access to MEDLINE, NLM's database of citations and abstracts in the fields of medicine, nursing, dentistry, veterinary medicine, health care systems, and preclinical sciences. MEDLINE is NLM's bibliographic database of citations and abstracts, currently from approximately 5,400 biomedical journals published in the United States and worldwide. Coverage extends back to 1946 with over 23 million citations.
