Mardina, Primata, Hesti Wijayanti, Abubakar Tuhuloula, Erita Hijriyati, and Sarifah. “Corncob Residue As Heterogeneous Acid Catalyst for Green Synthesis of Biodiesel: A Short Review”. Communications in Science and Technology 6, no. 2 (December 31, 2021): 60-68. Accessed January 19, 2022. https://cst.kipmi.or.id/journal/article/view/460.