Check out the notes, citations, and bibliographies of the books and articles you find. See what sources scholars are basing their work off of.
Also, if you find a work that you think is valuable to your topic, use Web of Science cited reference search or Google Scholar to see how that source is used in other scholarly conversations.
Below is a visual representation of citation mapping. The box in the center represents an article or a book you might find related to your topic. All of the boxes to the left are sources that your source draws upon and all of the boxes to the right are sources that use your source. It gives you the sense for how one good source can produce a lot of leads for other related sources!
