Automatic differentiation package - torch.autograd, PyTorch team, 2024 - Official documentation covering PyTorch's automatic differentiation engine (Autograd), computation graphs, and the mechanics of loss.backward().
Deep Learning, Ian Goodfellow, Yoshua Bengio, and Aaron Courville, 2016 (MIT Press) - A comprehensive textbook that details the theoretical foundations of backpropagation and automatic differentiation, including the chain rule.
Learning representations by back-propagating errors, David E. Rumelhart, Geoffrey E. Hinton, and Ronald J. Williams, 1986Nature, Vol. 323 (Springer Nature)DOI: 10.1038/323533a0 - The foundational academic paper that introduced the backpropagation algorithm for training multi-layer neural networks.