XGBoost Documentation, XGBoost Contributors, Current - A comprehensive guide for XGBoost's Python API, data structures, and training process.
XGBoost: A Scalable Tree Boosting System, Tianqi Chen and Carlos Guestrin, 2016KDD '16: Proceedings of the 22nd ACM SIGKDD International Conference on Knowledge Discovery and Data Mining (ACM)DOI: 10.1145/2939672.2939785 - The original academic paper describing the design and optimization techniques of the XGBoost algorithm.