PubMed Central is a free digital archive of biomedical and life sciences journal literature at the U.S. National Institutes of Health (NIH), developed and managed by NIH’s National Center for Biotechnology Information (NCBI) in the National Library of Medicine (NLM). All of the articles have been peer reviewed and published in professional journals.
PubMed Central exists by Congressional mandate. Any researcher funded in whole or in part by the National Institutes of Health must provide the resulting manuscript to the NIH for publication electronically. Concerned that so many journals were providing free abstracts of research but charging fees for access to full journal articles about research which had been paid for with public funds, the NIH adopted an open access policy.
What does this mean in real terms? It means you can read the full text of 42,807 journal articles related to Multiple Sclerosis.
Here’s the link: http://www.ncbi.nlm.nih.gov/sites/entrez?db=PubMed