Scirus
From Wikipedia, the free encyclopedia
Scirus is a comprehensive science-specific search engine. Like Citeseer and Google Scholar, it is focused on scientific information. Unlike Citeseer, Scirus is not only for computer sciences and IT and not all of the results are free (as an example, some results could be in the PubMed journal or on any of the Elsevier journals thus, a subscription would be required to access the article).