PubMed comprises more than 26 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations many include links to full-text content from PubMed Central and publisher websites.
DOAJ is an online directory that indexes and provides access to quality open access, peer-reviewed journals.
Bookshelf provides free online access to books and documents in the life sciences and healthcare.
PubMed Central is a free full-text archive of biomedical and life sciences literature at the U.S. Institutes of Health's National Library of Medicine (NIH/NLM).
BioMed Central is an STM (Science, Technology and Medicine) publisher with a large portfolio of peer-reviewed open access journals. Journals span all areas of biology, medicine and health.
PLoS. Non-profit organization of scientists committed to making the world's scientific and medical literature freely accessible to scientists and to the public ...
Use Google Scholar to find scholarly articles. The drawback is that not all articles are available for free.