Riszal, Akhmad, Sandy Dwi Hardin, Herry Wardono, M. Dyan Susila ES, and A. Yudi Eka Risano. “The Effect of the Use of Silica Sand Before and After Physical Activation on Acceleration of 4-Step Gasoline Motorcycle Engine”. Journal of Engineering and Scientific Research 4, no. 1 (June 23, 2022): 30–33. Accessed June 28, 2025. http://jesr.eng.unila.ac.id/index.php/ojs/article/view/98.