There are many repositories that archive and make works openly available. Articles in these repositories will often show up in a simple Google or Google Scholar search.
arXiv is an eprint archive for the fields of physics, mathematics, computer science, quantitative biology, quantitative finance, statistics, electrical engineering and systems science, and economics.
Knowledge Commons is a trusted nonprofit network where humanities scholars can create a professional profile, discuss common interests, develop new publications, and share their work.
PeerJ Preprints published screened, but not peer-reviewed, preprints in biological sciences, environmental sciences, medical sciences, health sciences, computer sciences and chemistry.
PubMed Central (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)
