A Guide to Library Research:
Locate Background Information
Julie Still, Reference Librarian
If you need quick information on something, just a fact or a statistic, or if you need background information to help you refine a topic idea, don't overlook reference books. For statistics, start with the Statistical Abstract of the United States, found at the reference desk. This is an encyclopedia of statistics gathered by the U.S. government. If your statistic isn't there ask a reference librarian what other statistical source you might use.
For brief or background information, don't overlook specialized encyclopedias, such as the Encyclopedia of Earth System Science or the Encyclopedia of Psychology. This type of resource can give you the history, development and current thought on your topic. They also often provide a brief bibliography, which would give a good start on finding standard works on the topic.