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).

The Library of Congress is the research library that officially serves the United States Congress and is the de facto national library of the United States.

DOAJ is a community-curated online directory that indexes and provides access to high quality, open access, peer-reviewed journals.

JURN is a free online search tool for the finding and downloading of free full-text scholarly works.

JSTOR is a digital library of academic journals, books, and primary sources.