Use a plus sign + in front of a word or a phrase to require its search A word or a phrase preceded by a + must be present in all pages returned
+"absentee voting"    +"assisted suicide"

Use a minus sign - in front of a word to exclude its search

If you wanted pages on fusion but not cold fusion you can prevent "cold" from being searched:
- cold fusion  
Use lower case letters to find words that are either lower and upper case
japanese internment
"world war ii"
Use parentheses around terms that are alike. Enter connectors in capital letters
(adolescents OR teenagers)
television AND children