Monica, Fitrya, Marisa Meliana Fitri, Iswandi Umar, Ali Amran, and Mulya Gusman. “Distribution of Potential Resources, Reserves and Use of Coal in Indonesia”. Science and Environmental Journal for Postgraduate 5, no. 2 (June 13, 2023): 119–126. Accessed April 24, 2026. http://senjop.ppj.unp.ac.id/index.php/senjop/article/view/191.