https://pubmed.ncbi.nlm.nih.gov
PubMed is a free search engine accessing primarily the MEDLINE database of references and abstracts on life sciences and biomedical topics. The United States National Library of Medicine at the National Institutes of Health maintain the database as part of the Entrez system of information retrieval. Wikipedia
Date launched: January 1996
Research center: United States National Library of Medicine (NLM)