Boolean logic - use AND, OR, NOT (sometimes AND NOT) to connect two or more search terms:
Truncation - the library catalog and most databases use special characters to make searching easier in certain situations. Check the help screens in the catalog or database you are using to see what the special characters are for that resource.
It's important to know that the catalog uses subject headings to organize books. When you know the right subject headings for your topic, you can search more efficiently. A simple way to find them is to start with a keyword search. When you find an article title that meets your needs, look for the subject headings assigned to that article. In most cases, those subject headings are hyperlinked and will take you to a list of articles with the same subject heading.