PubMed
PubMed covers biomedical literature published after 1960. It contains over 34 million bibliographic descriptions. Although PubMed is a bibligraphic and abstracts database, many full texts are provided by its publishers. Available to the public online since 1996, PubMed was developed and is maintained by the National Center for Biotechnology Information (NCBI), at the U.S. National Library of Medicine (NLM), located at the National Institutes of Health (NIH).