Regression Models and Life-Tables, David R. Cox, 1972Journal of the Royal Statistical Society. Series B (Methodological), Vol. 34 (Royal Statistical Society)DOI: 10.1111/j.2517-6161.1972.tb00899.x - The original publication introducing the Cox Proportional Hazards model and the concept of partial likelihood, forming the basis for survival analysis objective functions.
The Statistical Analysis of Failure Time Data, John D. Kalbfleisch, Ross L. Prentice, 2002 (Wiley)DOI: 10.1002/9781118032985 - A classic textbook providing a comprehensive treatment of survival analysis, including detailed explanations of the Cox PH model and its theoretical underpinnings.
Learning Task Parameters - XGBoost Documentation, XGBoost Contributors, 2023 (XGBoost Project) - Official documentation detailing the survival:cox objective function implementation within the XGBoost library, including input data format and considerations for usage.