Don’t search only using the name of your mathematician.
NAME + INFO ABOUT THE MATH
For example: JOHN NASH was known for advances in CRYPTOGRAPHY and GAME THEORY, specifically NASH EQUILIBRIUM, and for solving HILBERT'S NINETEENTH PROBLEM.
Good searches might be:
Choose "BOOKS" to find books and eBooks on a specific topic.
Use the book's index and table of contents to find your topic within the book.