Ervandi, Dhio, Aisyah Novriani, Andini Diva Luthfiyah, Fauzan Al Hamdani Siregar, and Tessy Octavia Mukhti. “Stratified Cox Regression Approach to Identifying Prognostic Factors for Survival in Breast Cancer Patients”. UNP Journal of Statistics and Data Science 3, no. 4 (November 30, 2025): 406–412. Accessed August 18, 2026. https://ujsds.ppj.unp.ac.id/index.php/ujsds/article/view/418.