Muhammad Amin, Budhi Oktavia, Anang Sedyohutomo, Lee Wah Lim, Muhammad Nurdin, “Ion Chromatographic Analysis of Sulfur Species (S2−, SO32−, and S2O32−) in Natural Geothermal Water Samples”, IJAST, vol. 29, no. 04, pp. 2460 - 2468, Jun. 2020.