The words you type into the search box affect your search results. Not all authors use the same language to describe similar topics, so you will need to try a variety of searches.
Create a list of possible words that could appear in a book or article related to your topic of interest
Come up with synonyms or related terms for those
Stick to using 2-4 nouns when searching
Example: "culture"
"cultural practices"
"customs"
"traditions"
What are keywords and why are they important?
The University of Houston Libraries provides an overview on how to enhance your search results using keywords.