Nugroho, Didit Budi, et al. “Evaluating the Fitting Performance of AGARCH(1,1), NAGARCH(1,1), and VGARCH(1,1) Models”. (IJCSAM) International Journal of Computing Science and Applied Mathematics, vol. 9, no. 2, Nov. 2023, pp. 44-49, https://journal.its.ac.id/index.php/ijcsam/article/view/4648.