For more information, consult the
The Chicago Manual of Style, 15th edition (Call number: READY REF Z253 U69).
Style Manual for Political Science, revised edition (Call number: REF JA86.A52 2001)It helps to narrow down and make your terms more specific.
For example if your research interest was freedom of speech and campaigns,
> The result should be more items on your topic, with less searching.