arXiv.org
Open access to 809,180 e-prints in Physics, Mathematics, Computer Science, Quantitative Biology, Quantitative Finance and Statistics.
Science.gov
Serves as a gateway to authoritative selected science information provided by 12 U.S. Government agencies, including research and development results. Science.gov brings together, through one interface, reliable resources selected by the respective agencies as important science information. Easy access options are provided through a search feature, a deep Web search feature for more detailed information, and a browse feature.
BioMed Central Open Acess
Provides access to peer-reviewed freely available journals in the biomedical fields.
Medline Plus
Health information including health topics, drugs and supplements, videos, health news, and more.