Keywords or search terms are the terms that you enter into your database search boxes. They represent the main topic or concepts of your research and are words used in everyday life.
Selecting keywords is a multi-step process:
Boolean Operators help narrow or broaden your set of results. The three basic boolean operators are: AND, OR, and NOT
Try using something called 'boolean logic'. You can use the words 'and' 'or' and 'not' to help narrow your results.