Raihan, Raihan, et al. “Forcasting Model Exsponensial Smoothing Time Series Rata Rata Mechanical Availability Unit Off Highway Truck CAT 777D Caterpillar”. POROS TEKNIK, vol. 8, no. 1, Mar. 2017, pp. 1-9, doi:10.31961/porosteknik.v8i1.375.