Gao, L.J., Q.Q. Shang, J.J. Zhou, G.M. Xiao, and R.P. Wei. “Esterification of Oleic Acid in Biodiesel Synthesis With SO42- ZrO2 MCM-41 As Catalyst”. Asian Journal of Chemistry 25, no. 12 (June 17, 2013): 6579–6583. Accessed November 25, 2024. https://asianpubs.org/index.php/ajchem/article/view/25_13_21.