Searching with keywords instead of phrases and connecting them with Boolean operators get you more targeted search results.
Using Boolean Operators
Boolean operators “AND”, “OR”, and “NOT” define relationships between words. How do they work?
“AND” – searches all of your search terms. Example: poverty and population and income. Records will contain all these terms. Fewer records are retrieved, but more precise.
“OR” – either or both terms are retrieved. Example: mouse OR rat. More records are retrieved, but less precise.
“NOT” – when used it excludes or ignores words from the search. Example: dating NOT marriage. Marriage is excluded from the search results. Using “NOT” can be tricky. You may eliminate a word associated with your topic which may provide additional information. This search helps to narrow your results but is very restrictive.