- ArXiv
- CiteSeerX
- EBSCO
- ePrint - Cryptology ePrint Archive
- Cat.inist - ~17 million bibliographic records (back to 1973) of documents held in the Inist-Cnrs collections and covering all fields of worldwide research in Science, Technology, Medicine, Humanities and Social Sciences.
- The Lancet - Neurology
- http://www.opticsinfobase.org/
- http://www.sciencedirect.com/
- http://www.worldcat.org/
- http://www.citeulike.org/
- http://myopenarchive.org/
- http://ovidsp.ovid.com/
- http://www.ssrn.com/ - Social Science Research Network
- http://zetoc.mimas.ac.uk/ - The monitoring and search service for global research publications