Large multidisciplinary search engine with results ranking and previews. Google Scholar indexes scholarly literature including journal articles. *Note: free public access available at http://scholar.google.com/
Index of citations for articles and conference papers on physics, electrical engineering, computers, and information technology. Contains abstracts.
Multidisciplinary index to scholarly and authoritative articles. Provides access to all three parts of the Citation Index: Arts and Humanities, Social Science and Science. Search by subject, author, journal title. Cited Reference Search finds articles that cite an author or article that you specify.