Searching the catalog with Subject Headings narrows results to materials that are specifically identified with the topic. Use the term (sources) in a subject search to identify primary source collections. A wildcard (*) can be used to collect variations on a term, such as (terroris*) including both "terrorism" and "terrorist."

Sample Subject Headings:

War on Terrorism, 2001-2009
Terrorism -- Prevention
Terrorism -- Computer network resources

A subject search for terrorism in Yemen may look like this:
SUBJECT: terroris* AND
SUBJECT: Yemen

A search about terrorism prevention and the United States could look like this:
SUBJECT: terrorism prevention AND
WORD(S): "united states"