Researchers can often find useful scholarship by identifying one particularly relevant book or article and seeing which sources that text cites. With printed texts, this process might involve checking the bibliography.
In some databases, you can also trace citations forward in time and find subsequent material that cites a particularly useful resource. Google Scholar is the best database for tracing citations in the humanities. To do so:
While this strategy is very useful, keep in mind that the list of citations will not always be comprehensive.