Abiodun, Alfred Adewole, Benjamin Agboola Oyejola, and Kazeem Adedayo Adeleke. 2019. “An Empirical Comparison Between Partial Likelihood and Penalized Partial Likelihood Estimators for Semi-Parametric Non-Proportional Hazards Models With Frailty”. Malaysian Journal of Applied Sciences 4 (1), 1-14. https://journal.unisza.edu.my/myjas/index.php/myjas/article/view/124.