I can't speak about Mathematics of Poker, since I haven't read it, but both Janda's Applications of NL Hold Em and Modern Poker Theory are good for teaching you the foundational knowledge about game theory. The applied knowledge in Modern Poker Theory is more up to date with charts from solvers and such, but realistically you read the books to understand the underlying concepts. Then use videos, solvers etc to work on your game after you have a good grasp of the underlying theory.