Norwazan, A. R., et al. “Performances of Jatropha and Waste Cooking Oil Biodiesel Blends Fuel Combustion Using Diesel Engine”. International Journal of Integrated Engineering, vol. 12, no. 5, June 2020, pp. 130-6, https://penerbit.uthm.edu.my/ojs/index.php/ijie/article/view/6093.