“Karakteristik Batubara Peringkat Rendah Formasi Bobong Dan Implikasinya Terhadap Coal Liquefaction ”. Jurnal Geomine 8, no. 01 (April 30, 2020): 17–24. Accessed June 28, 2025. https://jurnal.fti.umi.ac.id/index.php/JG/article/view/1387.