Reinforcement Learning: An Introduction, Richard S. Sutton and Andrew G. Barto, 2018 (MIT Press) - A widely recognized textbook that provides a thorough introduction to reinforcement learning concepts, including the detailed derivation and explanation of Bellman expectation equations for value functions.
Dynamic Programming, Richard Bellman, 1957 (Princeton University Press) - The original work that introduced the concept of dynamic programming and the Bellman equations, which form the mathematical backbone for solving sequential decision-making problems.
Reinforcement Learning Lecture 3: Dynamic Programming, David Silver, 2015 - Lecture slides from a university course on reinforcement learning, offering a clear and concise explanation of Bellman expectation equations within the context of policy evaluation and dynamic programming.