Peiró, Amado. “Changes in the Unconditional Variance and Autoregressive Conditional Heteroscedasticity”. International Journal of Economics and Financial Issues 6, no. 4 (October 21, 2016): 1338–1343. Accessed January 25, 2025. https://mail.econjournals.org.tr/index.php/ijefi/article/view/2643.