Rian C Sondakh, Erliza Hambali, and Nastiti S Indrasti. “Esterification Bio-Oil Using Acid Catalyst and Ethanol”. International Journal of Engineering and Management Research 8, no. 5 (October 31, 2018): 137–141. Accessed March 17, 2026. https://ijemr.vandanapublications.com/index.php/j/article/view/599.