Google Scholar http://scholar.google.com/
Google Scholar provides a simple way to broadly search for scholarly literature.
IPL2 http://www.ipl.org/
IPL2 is a combination of the Internet Public Library and Librarian’s Internet Index.
Library of Congress – by Topic http://www.loc.gov/topics/
A new (2009) set of reference pages designed to make it easier to find the Library’s diverse and extensive online collections.
