Academic Search Premier Provides multidisciplinary content, including PDF backfiles to 1975 or further for well over one hundred journals, as well as searchable cited references for more than 1,050 titles.
Access the world’s leading scholarly literature in the sciences, social sciences, arts, and humanities and examine proceedings of international conferences, symposia, seminars, colloquia, workshops, and conventions.
Zentralblatt Math Database the complete run (1931- ) of Zentralblatt fur Mathematik is searchable at this German site. You can get up to 3 results from each search (demo mode -- we do not have a subscription). Free service: Citation checker.
A digital archive of important mathematical publications of the period 1868-1942 and a database based on the "Jahrbuch Ÿber die Fortschritte der Mathematik". Links to the World Digital Mathematical Library.
Social science data sets are available for downloading; coverage includes but is not limited to the U.S. Census, crime and criminal justice, foreign and national opinion polls, health, consumer surveys, and historical data sets.