Roy Sianturi (2025) “Energy Analysis of Geothermal Resources in the Volcanic Zone of North Sumatra for Renewable and Reliable Power Supply”, International Journal of Energy Systems and Materials Innovation, 1(1), pp. 09–15. Available at: https://journal.gioedutech.id/index.php/IJESMI/article/view/2 (Accessed: 23 January 2026).