Ismail, M., M. Fawzi, F. Zulkifli, and S. Osman. “Effects of Fuel Ratio on Performance and Emission of Diesel-Compressed Natural Gas (CNG) Dual Fuel Engine”. Journal of the Society of Automotive Engineers Malaysia, vol. 2, no. 2, Apr. 2021, pp. 157-65, doi:10.56381/jsaem.v2i2.86.