Mahmudah, Umi. “A GARCH Model for Forecasting Volatility of Oil and Gas Exports in Indonesia”. JURNAL ILMIAH MATEMATIKA DAN TERAPAN 21, no. 2 (December 16, 2024): 131 - 143. Accessed February 5, 2025. https://bestjournal.untad.ac.id/index.php/JIMT/article/view/16836.