Iqbal, M. et al. 2014. Eo-Oligocene Oil Shales of the Talawi, Lubuktaruk, and Kiliranjao Areas, West Sumatra: Are they potential source rocks?. Indonesian Journal on Geoscience. 1, 3 (Dec. 2014), 135–149. DOI:https://doi.org/10.17014/ijog.1.3.135-149.