These databases are excellent resources, especially when you are beginning your research.
Boolean Operators
Many catalogs and databases allow the user to put a search string together using the boolean operators AND, OR, or NOT.
Truncation
In many catalogs and databases, truncation is represented by an asterisk (*). To use truncation, enter the root of a search term and replace the ending with an *.
For example, type behav* to find the words behave, behavior, behaviour, behavioral, behaviorism, etc..