Heryanto, Rachmat, and Suyoko Suyoko. “Karakteristik Batubara Di Cekungan Bengkulu”. Indonesian Journal on Geoscience 2, no. 4 (December 28, 2007): 247–259. Accessed March 14, 2025. https://ijog.geologi.esdm.go.id/index.php/IJOG/article/view/42.