Adji Achmad Rinaldo Fernandes, Diah Ayu Widiastuti, Nurjannah. “Smoothing Spline Semiparametric Regression Model Assumption Using PWLS Approach ”. International Journal of Advanced Science and Technology, Vol. 29, no. 04, Apr. 2020, pp. 2059 -70, http://sersc.org/journals/index.php/IJAST/article/view/9138.