Zetra, Yulfi, Hendra Siswanto Kusuma, Fina Riandra, Imam B. Sosrowidjojo, and R.Y. Perry Burhan. “The Oxygenated Biomarker As an Indicator of Origin and Maturity of Miocene Brown Coal, Sangatta Coal Mines, East Kalimantan”. Indonesian Journal on Geoscience 5, no. 2 (May 8, 2018): 107–116. Accessed December 4, 2024. https://ijog.geologi.esdm.go.id/index.php/IJOG/article/view/289.