Warsono, Warsono, Edwin Russels, Wamiliana Wamiliana, Widiarti Widiarti, and Mustofa Usman. 2019. “Vector Autoregressive With Exogenous Variable Model and Its Application in Modeling and Forecasting Energy Data: Case Study of PTBA and HRUM Energy”. International Journal of Energy Economics and Policy 9 (2):390-98. https://mail.econjournals.com/index.php/ijeep/article/view/7223.