Andalaluna, Lebong, and Masatoshi Sugioka. 2005. “Enhancement Effect of Hydrogen Sulfide Over Metal Ion-Exchange Mesoporous Silicate FSM-16 for Acid Catalyzed Reactions”. ASEAN Journal of Chemical Engineering 5 (1), 76-83. https://journal.ugm.ac.id/v3/AJChE/article/view/7637.