Talia, A., Lasker Pangarapan Sinaga and Lasker Pangarapan Sinaga (2026) “Optimization of the Electricity Economics System (EES) in Supporting National Energy Policy Using a Tri-Level Programming Approach”, JURNAL ILMIAH MATEMATIKA DAN TERAPAN, 23(1), pp. 26 - 40. doi: 10.22487/2540766X.2026.v23.i1.18081.