WASET
    Osama H. Ghazal and  Yousef S. Najjar and  Kutaeba J. AL-Khishali ,  Effect of Inlet Valve Variable Timing in the Spark Ignition Engine on Achieving Greener Transport.   journal   = {International Journal of Mechanical and Mechatronics Engineering}, [online]. World Academy of Science, Engineering and Technology.
    October 2011, vol. 59(11). 2536 - 2540
    [viewed 25 April 2024]. Available from: https://publications.waset.org/pdf/17401.