“PERFORMANCE AND EVALUATION ON FOUR STORKE SINGLE CYINDER DI DIESEL ENGINE WITH TRAPEZOIDAL GROOVES ON PISTON CROWN”, IJFANS, vol. 11, no. 12, pp. 9756–9763, Jan. 2022, Accessed: Aug. 26, 2026. [Online]. Available: http://ijfans.org/index.php/Journal/article/view/13842