Subject Searching in the Clarke catalog 

Searching for subjects using the Subject Keyword or Subject alphabetical index to search can be tricky because they do not work like the General Keyword Index. Instead, you have to use special terms called Library of Congress Subject Headings (abbreviated as LCSH). Be sure to click on Library of Congress Subject Headings to learn how to use them.

If you search the Subject Keyword Index using words not in the LSCH you may not get much back. 

For instance, if you entered a Subject Heading search for: world war two you would get no books!

But if you searched using the LCSH term, world war, 1939-1945 you'd see the library has many books.