Zainal Abidin, Shaiful Fadzil, et al. “Investigation of Cylinder Deactivation (CDA) Application on a Naturally Aspirated Engine”. International Journal of Integrated Engineering, vol. 14, no. 6, Nov. 2022, pp. 125-34, https://penerbit.uthm.edu.my/ojs/index.php/ijie/article/view/7980.