Reinforcement Learning: An Introduction, Richard S. Sutton, Andrew G. Barto, 2018 (MIT Press) - This book is the definitive reference for introductory and intermediate reinforcement learning concepts, covering function approximation and various feature engineering techniques discussed.
Playing Atari with Deep Reinforcement Learning, Volodymyr Mnih, Koray Kavukcuoglu, David Silver, Alex Graves, Ioannis Antonoglou, Daan Wierstra, Martin Riedmiller, 2013arXiv preprint arXiv:1312.5602DOI: 10.48550/arXiv.1312.5602 - This foundational paper introduced Deep Q-Networks (DQN), demonstrating how deep neural networks can learn effective feature representations directly from raw, high-dimensional inputs to achieve high performance in control tasks.
Deep Learning, Ian Goodfellow, Yoshua Bengio, Aaron Courville, 2016 (MIT Press) - This comprehensive textbook provides a thorough treatment of neural networks and deep learning, including how they learn hierarchical feature representations from raw data, which is important for understanding learned features in modern reinforcement learning.