Nik Rosli Abdullah, Nafis Syabil Shahruddin, Rizalman Mamat, Aman Mohd. Ihsan Mamat, and Aminuddin Zulkifli, “Effects of Air Intake Pressure on the Engine Performance, Fuel Economy and Exhaust Emissions of A Small Gasoline Engine”, J. Mech. Eng. Sci., vol. 6, no. 1, pp. 949–958, Jun. 2014.