An Introduction to Statistical Learning: With Applications in R, Gareth James, Daniela Witten, Trevor Hastie, and Robert Tibshirani, 2021 (Springer)DOI: 10.1007/978-1-0716-1418-1 - A widely used introductory textbook covering the core concepts of statistical learning, including the distinction between classification and regression, and foundational classification algorithms.
Pattern Recognition and Machine Learning, Christopher M. Bishop, 2006 (Springer)DOI: 10.1007/b93563 - A comprehensive and foundational textbook providing a detailed theoretical treatment of classification and other machine learning concepts, emphasizing probabilistic approaches.
User Guide: Classification, scikit-learn developers, 2023 - Official documentation for scikit-learn, offering a practical overview of classification tasks, common algorithms, and usage examples for a leading machine learning library.
Supervised Learning (Lecture Notes), Andrew Ng, 2018 (Stanford University) - Lecture notes from a highly influential Stanford machine learning course, providing a clear and mathematically rigorous introduction to supervised learning, including classification problems.