S, Omar, Ahmad F.H, Hassan H, Faujan N.H, and Basri M. “Enzymatic Esterification of Betulinic Acid”. Malaysian Journal of Science 24, no. 1 (January 31, 2005): 97–98. Accessed July 3, 2024. https://sare.um.edu.my/index.php/MJS/article/view/8937.