Ulfah, M., H. Suherman, M. Laniwati, and S. Subagjo. “Methanol Dehydration to Dimethyl Ether over Modified -Al2O3 With Acid, Base and Zeolite (NaA and NaX)”. ASEAN Journal of Chemical Engineering, Vol. 20, no. 2, Dec. 2020, pp. 109-1, https://dev.journal.ugm.ac.id/v3/AJChE/article/view/9117.