N. S. A. Manab, H. Veny, A. Gusniah, S. Sulaiman, and N. Aziz, “Stepwise Methanolysis of Waste Cooking Oil Using Immobilized Thermomyces lanuginose Lipase within Ultrasonic-assisted Condition”, ASEAN J. Chem. Eng., vol. 21, no. 1, pp. 19-26, Jun. 2021.