Satriana, S., dan M. D. Supardan. Kinetic Study of Esterification of Free Fatty Acid in Low Grade Crude Palm Oil Using Sulfuric Acid. Vol. 8, no. 1, Desember 2008, hlm. 1-8, https://jurnal.ugm.ac.id/v3/AJChE/article/view/7691.