“Pengukuran Potensi Pemanfaatan Listrik Tenaga Sinar Matahari Di Kabupaten Langkat”. Jurnal Sistem Teknik Industri 22, no. 1 (January 30, 2020): 45–51. Accessed February 4, 2026. https://idjpcr.usu.ac.id/jsti/article/view/3257.