Remember to use filter bubbles to limit Google search results. Here, by using .edu, you can see results come from Princeton, U of Rochester, and one of the California State Universities. Instead of "morality plays", type in your own search terms and see what other scholars are doing with your keywords.
Use Wikipedia for your PREresearch. Keywords can be gleaned from general information - see the words highlighted in blue. Furthermore, the list of references at the end of an article not only shows you that the works is (somewhat) scholarly, sources were cited, but these links will lead you to more information.