Calculus: Early Transcendentals, James Stewart, 2015 (Cengage Learning) - A widely used textbook that provides a comprehensive and accessible introduction to multivariable calculus, including the fundamental concepts and notation of partial derivatives.
Mathematics for Machine Learning, Marc Peter Deisenroth, A. Aldo Faisal, and Cheng Soon Ong, 2020 (Cambridge University Press) - Specifically tailored for machine learning, this book introduces partial derivatives and their notation within the context of optimization and neural networks.
Multivariable Calculus (18.02SC), Denis Auroux, Arthur Mattuck, Jeremy Orloff, John Lewis, Heidi Burgiel, Christine Breiner, David Jordan, Joel Lewis, 2010 (MIT OpenCourseWare) - An authoritative online course providing video lectures, notes, and problem sets covering multivariable calculus topics, including a clear explanation of partial derivative notation.
Deep Learning, Ian Goodfellow, Yoshua Bengio, and Aaron Courville, 2016 (MIT Press) - This foundational text on deep learning includes a mathematics background appendix that concisely reviews differential calculus, including partial derivative notation relevant for understanding neural network optimization.