W. Warsono, E. Russel, W. Wamiliana, W. Widiarti, and M. Usman, “Modeling and Forecasting by the Vector Autoregressive Moving Average Model for Export of Coal and Oil Data (Case Study from Indonesia over the Years 2002-2017)”, IJEEP, vol. 9, no. 4, pp. 240–247, Jun. 2019.