General Reference

ABC-CLIO eBook Collection
This gives you access to eBooks for the study of history and the social sciences.
Acronyms, Initialisms, and Abbreviations Dictionary
Features definitions of a wide variety of acronyms, initialisms, abbreviations and similar contractions. New terms from subject areas such as associations, education, the Internet, medicine and others are now included.
Credo Reference
Links to various subject encyclopedias in areas such as art, history, law, literature, philosophy, science, and technology.
Gale Virtual Reference Library
Offers a large collection of reference books that you can view and search online.
Oxford Digital Reference (Shelf List)
Has around 2 million digitized entries in 25 different subject areas.