Barusman, M. Yusuf S., and Appin Purisky Redaputri. “Decision Making Model of Electric Power Fulfillment in Lampung Province Using Soft System Methodology”. International Journal of Energy Economics and Policy, vol. 8, no. 1, Jan. 2018, pp. 128-36, https://econjournals.com/index.php/ijeep/article/view/5932.