"PubMed CentralĀ® (PMC) is a free full-text archive of biomedical and life sciences journal literature at the U.S. National Institutes of Health's National Library of Medicine (NIH/NLM)."
"Medrxiv is an Internet site distributing unpublished manuscripts about health sciences. It distributes complete, but unpublished manuscripts in the areas of medicine, clinical research, and related health sciences without charge to the reader." (Wikipedia)
PLOS is a nonprofit, Open Access publisher empowering researchers to accelerate progress in science and medicine by leading a transformation in research communication.
NoodleTools is an online research management platform that helps you evaluate information, build accurate citations, archive source material, take notes, outline topics, and prepare to write. Sign in with Google.