Yudo, E., A. Ariyanto, E. Erwansyah, Z. S. Suzen, S. Sugiyarto, Y. Dharta, and Z. Zulfitriyanto. “Effect of Heat Treatment and Tempering Process on the Hardness of S55c Steel As A Cutting Blade Material for Plastic Shredding Machines”. Integrated Science Education Journal, Vol. 7, no. 1, Jan. 2026, pp. 127-36, https://cahaya-ic.com/index.php/ISEJ/article/view/2461.