Credo Reference is an excellent starting point--providing over 500 full-text reference sources.
The reference sources listed on this page provide the following types of information:
Find additional reference sources by searching LVC Books. Click on Power Search, choose Type, choose Reference, and search for your keywords.
Image: Donna Miller. Wordle.net
Print subject encyclopedias, available in Bishop Library, behind the DVD's.
Image Source: US Dept. Energy. Public Domain. Wikimedia Commons.