Getting the Most out of PubMed Medline: Boolean Operators

Boolean Operators link concepts and are used to broaden or narrow your search. Briefly, here's how they work:

AND - finds results with your all search terms.  AND narrows your search.

OR - finds results with any of your search terms.  OR broadens your search.

NOT - finds results with only one of your search terms.  NOT narrows your search.