Sevilla RP, Yatini Y, Muhlis F. Coal Quality Distribution Analysis Based on Gamma Ray Log and Gamma-Gamma Ray Log in Area X, East Kalimantan. etj [Internet]. 2026 Jul. 13 [cited 2026 Sep. 28];11(07):10930-9. Available from: https://everant.org/index.php/etj/article/view/2953