Unlike Google, library databases can't understand an entire sentence. So you'll need to break your topic down into the most important ideas - the KEYWORDS.
Example Topic: How prevalent is PTSD among refugee populations?
The specifics of your topic will matter when selecting sources, but for searching you only need the most essential components.
Keywords: PTSD, refugees
Most words have synonyms that mean the same, or very similar, things. For each keyword in your topic, try to come up with at least one synonym. Not all keywords will have synonyms, but many do!
Keep an Eye Out
Sometimes scholars use terms that you might not be familiar with, or which might mean something very specific within the discipline. While searching, look for unfamiliar terms or words that show up a lot. Try searching for those and see if you find more relevant sources.
Most library databases have search tools built in. Try some of these:
Look on the left and right of your search results, or for an "advanced search" page to find these tools - and more!
You can evaluate any source using the 5 W's:
Use the operator AND to find only sources that mention both keywords.
This search will bring back fewer results than searching either keyword on its own.
Use the OR operator to expand your search with additional keywords.
This will find sources that include either word, so you'll see more results than by searching for just one keyword.
Use the “QUOTES” strategy to search for several words in a phrase.
This will bring back results that only use that exact phrase.