A reference source or tool can provide context for your research topic, including names, dates, events and related resources or further reading. They are a great place to start your research.
For more information, see:
What are Reference Sources? UofT Libraries
Check terms, facts, timelines, context, terminologies, biographies, etc.
P Gowers, T., Barrow-Green, J., & Leader, I. (2008). The Princeton companion to mathematics (Core Textbook). Princeton University Press.