Farikhah, Ginda Putri, Wirda Udaibah, and Mulyatun Mulyatun. 2021. “Synthesis and Characterization of SO42- KCC-1 Catalyst As an Alternative Candidate for Simultaneous Esterification and Transesterification Reactions”. Journal of Natural Sciences and Mathematics Research 7 (1):1-6. https://journal.walisongo.ac.id/index.php/JNSMR/article/view/6797.