Anggayana, Komang, Agus Haris Widayat, and Sri Widodo. “Depositional Environment of the Sangkarewang Oil Shale, Ombilin Basin, Indonesia”. Journal of Engineering and Technological Sciences 46, no. 4 (December 15, 2014): 420-435. Accessed January 3, 2026. https://journals.itb.ac.id/index.php/jets/article/view/354.