Mubashir, Muhammad, Yeong Yin Fong, Lau Kok Keong, and Mohd. Azmi Bin Sharrif. 2014. “Synthesis and Performance of Deca- Dodecasil 3 Rhombohedral (DDR)-Type Zeolite Membrane In CO2 Separation– A Review”. ASEAN Journal of Chemical Engineering 14 (2), 48-57. https://dev.journal.ugm.ac.id/v3/AJChE/article/view/8852.