All Academic
   A searchable database of academic publications: journals, working papers, convention papers and magazine articles. Also has an A-Z list of links to online journals.
   http://www.allacademic.com/

BASE: Bielefeld Academic Search Engine
   Searches scholarly internet resources from all academic disciplines. Provides a list of the sources indexed.
   http://www.base-search.net/

Google Scholar
   Provides a search of scholarly literature across many disciplines and sources, including theses, books, abstracts and articles.
   http://scholar.google.com/