NORDIN BIN SALLEH, MUHAMMAD ALIFF NAZMI, and Said Ahmad. “Surface Integrity Study of AISI D2 Steel Using Powder Mixed RBD Palm Oil-Based Dielectric Fluid in Electrical Discharge Machining Process”. Research Progress in Mechanical and Manufacturing Engineering, vol. 6, no. 2, Dec. 2025, pp. 74-89, https://publisher.uthm.edu.my/periodicals/index.php/rpmme/article/view/20896.