PubMed is a bibliographic database including 28 million references to Biomedicine and Health from MEDLINE, other journals on Life Science, and books available online. It is a free resource developed by the National Center for Biotechnology Information (NCBI) at the National Library of Medicine. Citations and abstracts in PubMed goes from Biomedicine to Health Education, including disciplinary fields such as Life Science, Behavioral Science, Chemistry, and Bioengineering. Moreover, PubMed grants access to various relevant websites and links to other NCBI resources for Molecular Biology. 

PubMed LinkOut function grants access to a wide range of online resources, such as full text publications, biological databases, information on consumers' health, research tools, etc. More than 60% of the PubMed records are linked to the full text on publishers' websites or PMC (PubMed Central). More than 90% of the records in the last 10 years are linked to the full text of the article. In order to access it, a registration and/or a subscription to the resource may be required.