Boolean operators, or connectors, can be used to combine
or exclude search terms. Boolean operators can be used with controlled
vocabulary or keyword searching. These operators include
AND,
OR ,
NOT.
AND is used to combine terms and retrieves records
that contain all the terms in each record. This operator narrows and focuses
a search.
OR is used to combine terms and retrieves records
that contain one or more of the terms in each record. This operator expands a search.
NOT is used to exclude a term and retrieves records
that do not contain the specified term. This operator narrows a search.
Find
Articles Using Library Databases 
