Shamsuddin, Muhammad Syahir, and Abd Fathul Hakim Zulkifli. 2021. “Prediction of Performance and Emission of CNG-Diesel Dual Fuel Engine Using Response Surface Methodology”. Progress in Engineering Application and Technology 2 (2): 790–809. https://penerbit.uthm.edu.my/periodicals/index.php/peat/article/view/704.