Hassan, N. ., and A. M Saleh. “EXHAUST GAS RECIRCULATION EFFECT ON COMBUSTION AND EMITTED NOX IN A SPARK IGNITION ENGINE USING HIGH OCTANE NUMBER FUEL”. THE IRAQI JOURNAL FOR MECHANICAL AND MATERIALS ENGINEERING, vol. 21, no. 2, June 2021, pp. 80-95, doi:10.32852/iqjfmme.v21i2.545.