To search references that contain a specific sequence of letters, simply add an asterisk following the partial word. For example, annuit* will provide you with information about annuity, annuities, annuitant, etc.
To search for an exact phrase, you can put quotation marks around the phrase. Your results will always refer to the exact phrase, just as you entered it.
To search each of the individual words in a phrase, you can enter the phrase without asterisks, quotation marks, etc.