Razon, Luis F, Carlito M Salazar, Hiroo Niiyama, and Long The Nam Doan. 2007. “Preparation and Activity of Precipitated Ni-MgO/Al2O3 Catalysts for the Partial Oxidation of Methane”. ASEAN Journal of Chemical Engineering 7 (2), 108-9. https://dev.journal.ugm.ac.id/v3/AJChE/article/view/7683.