NumPy documentation, NumPy Developers, 2023 - The official and most comprehensive resource for all NumPy features, covering ndarray structure, performance, and API details.
Python for Data Analysis: Data Wrangling with Pandas, NumPy, and IPython, Wes McKinney, 2022 (O'Reilly Media) - A definitive guide by the creator of Pandas, explaining NumPy's role in the Python data stack with practical examples and explanations of core concepts like vectorization and broadcasting.
SciPy Lecture Notes, Gael Varoquaux, Emmanuelle Gouillart, and Olivier Martin, 2022 - A free, high-quality educational resource covering NumPy, SciPy, Matplotlib, and other scientific Python tools, with explanations of core concepts and practical applications.