MathSciNet: Extensive coverage of the mathematical sciences literature, with expert reviews, using the Mathematics Subject Classification. From the American Mathematical Society.

zbMATH (Zentralblatt MATH): Comprehensive abstracting and reviewing service for pure and applied mathematics. The database uses the Mathematics Subject Classification. Free access is limited to 3 results, and filter functions are disabled.

Concept mapping can help you articulate, clarify, and organize your knowledge of a research project. Maps can grow with you, and be used to communicate your progress.