Idrus, A., Setijadji, L. D., & Thamba, F. (2011). Geology and Characteristics of Pb-Zn-Cu-Ag Skarn Deposit at Ruwai, Lamandau Regency, Central Kalimantan. Indonesian Journal on Geoscience, 6(4), 191–201. https://doi.org/10.17014/ijog.6.4.191-201