When you search in academic databases, keywords will give you the best results. Use one to three keywords to express the main concepts in your research question. Combine keywords with AND, OR, or NOT. (See Using Boolean Operators.)
Tip: Put phrases in quotes--such as "climate change"-- to search for the exact words.
Boolean Operators sound like highly technical tools, however, they are simply the words AND, OR, and NOT. You use these terms to connect keywords and thus, to search more effectively and efficiently.
Use AND to connect two unlike words and narrow your search* -- useful if you get too many results
Use OR to connect to like words and broaden your search -- useful if you get too few results
Use NOT to exclude a word from your search results.