Veza, I., V. Muhammad, R. Oktavian, D. W. Djamari, and M. F. Muhamad Said. “Effect of COVID-19 on Biodiesel Industry: A Case Study in Indonesia and Malaysia”. International Journal of Automotive and Mechanical Engineering, vol. 18, no. 2, June 2021, pp. 8637 -, doi:10.15282/ijame.18.2.2021.01.0657.