Juliah Ratnaningsih, D. ., Saefuddin, A. ., & Kurnia, A. . (2020). Stratified-Extended Cox with Frailty Model for Non-Proportional Hazard: A Statistical Approach to Student Retention Data from Universitas Terbuka in Indonesia. Thailand Statistician, 19(1), 208–227. Retrieved from https://ph02.tci-thaijo.org/index.php/thaistat/article/view/242826