Some tips for searching "SAGE Knowledge Books and Reference" :click on the Advanced Search link and put in search terms related to your specific topic. Scroll down to "Content Types" and under the reference category, select Encyclopedias and any other relevant items.
One source of background information is Google
Try using the advanced Google search interface.
Evaluate what you find, using the "Evaluating .Web Resources" box; see the next box.
Web resources can be rich sources of information on a topic, but when conducting research, it's important to consider the quality and accuracy of sites you visit on the open web. Use the CRAPP test to determine whether a web resource is trustworthy: