Setyono, G., and N. Kholili. “Combustion Conduct Of A Single-Cylinder Spark-Ignition Affected By Ethanol Fuel Mixtures of Supplement Hydroxy Gas (HHO)”. Jurnal Teknik Mesin, Vol. 14, no. 2, Dec. 2021, pp. 125-9, doi:10.30630/jtm.14.2.669.