Research proceeds in several stages. When you are exploring and focussing a topic into a research question, it's often helpful to consult with some reference sources. In some cases, an academic encuyclopedia source can function as a kind of "literature review lite" and point you in the direction of research that will help with your literature review.
Here are some general reference databases. There's a variety of useful sources, so explore.
The resources here aren't traditional reference sources, but they may still be useful when you are exploring, narrowing and focusing your topic into a research question. Additionally, they may provide links to sources for scholarly journal articles, data sources and other information which you may need.