Put quotation marks " " around phrases to search the term as a phrase. Otherwise the database or Google may separate the words.
"bipolar disorder" "attachment theory" "sex roles" "child development"
Refine your search results using Boolean operators. The three most common Boolean operators are AND, OR, and NOT, but there are others available. The operators AND and NOT will narrow your search and OR will usually increase your search results.
AND - Use AND to find resources with all of your search terms.
“bipolar disorder” AND treatment
“sex differences” AND “verbal ability”
depression AND "college students"
schizophrenia AND genetics
OR - Use OR to find articles with either search term in them.
"post traumatic stress disorder" OR PTSD
"eating disorders" OR bulimia OR anorexia
NOT - Use NOT to eliminate terms you do not want in results.
depression NOT "postpartum depression"