Basalamah, Salsabila, and Edy Widodo. “Response Surface Model With Comparison of OLS Estimation and MM Estimation”. Indonesian Journal of Statistics and Its Applications 5, no. 2 (June 30, 2021): 273–283. Accessed January 18, 2025. https://journal-stats.ipb.ac.id/index.php/ijsa/article/view/817.