<unk>  (Medical Literature Analysis and Retrieval System Online, or MEDLARS Online) is a bibliographic database of life sciences and biomedical information. It includes bibliographic information for articles from academic journals covering medicine, nursing, pharmacy, dentistry, veterinary medicine, and health care.<unk>  also covers much of the literature in biology and biochemistry, as well as fields such as molecular evolution. Compiled by the United States National Library of Medicine (NLM),<unk>  is freely available on the Internet and searchable via PubMed and NLM's National Center for Biotechnology Information's Entrez system.
MEDLINE
WikEM
CINAHL
PubMed
AO Foundation
ICE 
MedlinePlus
ICECI