Unlike Google, library databases cannot process an entire sentence. You will need to break your topic down into the most important ideas - the keywords.
The specifics of your topic will matter when selecting sources, but for searching you only need the most essential components:
Keywords: expressionists, modern art
Most words have synonyms that mean the same, or very similar, things.
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 reoccur
Try searching for those and see if you find more relevant sources.
Most library databases have built-in filters to refine your search. Try some of these:
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.