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 foundational paper introducing XGBoost, detailing the exact greedy algorithm, its mathematical formulation, and computational aspects.
XGBoost Documentation - Tree Methods, XGBoost Contributors, 2024 - Official documentation explaining the implementation details, parameters, and various tree construction algorithms in XGBoost, including the exact greedy split finding.
The Elements of Statistical Learning: Data Mining, Inference, and Prediction, Trevor Hastie, Robert Tibshirani, and Jerome Friedman, 2009 (Springer) - A classic textbook providing comprehensive theoretical foundations for statistical learning, including decision trees and ensemble methods like gradient boosting, which are essential for understanding split finding algorithms.