C. Huynh, K. Joon-Kyoung, N. Ki-Cholo, L. Jong-Tai, and M. Pham, “FEASIBILITY OF BACKFIRE CONTROL AND PERFORMANCE USING CHANGES OF VALVE OVERLAP PERIOD FOR A HYDROGEN-FUELED ENGINE WITH EXTERNAL MIXTURE”, Science and Technology Development Journal, vol. 12, no. 14, pp. 77-85, Aug. 2009.