PubMed Central (PMC) is a free archive of biomedical and life sciences journal literature at the U.S. NIH National Library of Medicine (NIH/NLM), with selected open access to more than 2.6 million articles. From a PubMed citation, notice the bottom right links to:
Please note, however, that free access does not mean that there is no copyright protection. As described on PMC's copyright page, publishers and individual authors continue to hold copyright on the material in PMC and users must abide by the terms defined by the copyright holder.
Locating the full text of an article: