Regression Quantiles, Roger Koenker and Gilbert Bassett Jr., 1978Econometrica: Journal of the Econometric Society, Vol. 46 (The Econometric Society)DOI: 10.2307/1913643 - Original paper introducing the concept of quantile regression, laying the theoretical foundation for modeling conditional quantiles.
Greedy Function Approximation: A Gradient Boosting Machine, Jerome H. Friedman, 2001The Annals of Statistics, Vol. 29DOI: 10.1214/aos/1013203451 - Foundational paper on Gradient Boosting Machines (GBM), detailing the general algorithm for minimizing arbitrary differentiable loss functions, relevant for adapting GBM to quantile regression.
The Elements of Statistical Learning: Data Mining, Inference, and Prediction, Trevor Hastie, Robert Tibshirani, and Jerome Friedman, 2009 (Springer) - Authoritative textbook covering statistical learning, including comprehensive discussions on gradient boosting and various loss functions, providing context for quantile regression.
sklearn.ensemble.GradientBoostingRegressor, Scikit-learn developers, 2024 - Official documentation for Scikit-learn's GradientBoostingRegressor, detailing the 'quantile' loss option for practical implementation.