“Searches over 36 databases and 1,850 selected websites, offering 200 million pages of authoritative U.S. government science information, including research and development results.”
A nonprofit Open Access publisher, PLOS is an "innovator and advocacy organization with a mission to accelerate progress in science and medicine by leading a transformation in research communication."
“Contains Darwin's complete publications, 20,000 private papers, the largest Darwin bibliography and manuscript catalogue and hundreds of supplementary works.”