Alrubaiy, Ahmed AAG., et al. “Experimental Investigation of Diesel-WCOB Engine Performance With A Small Proportion of Ethanol Isobutanol As A Fuel Additive”. International Journal of Integrated Engineering, vol. 15, no. 7, Dec. 2023, pp. 82-88, https://penerbit.uthm.edu.my/ojs/index.php/ijie/article/view/14520.