Visuttipitukul, Patama, Chuleeporn Paa-rai, and Kuwahara Hideyuki. 2017. “Effect of Decarburization on Microstructure of DC-Plasma Nitrided H 13 Tool Steel”. Journal of Metals, Materials and Minerals 16 (2). Bangkok, Thailand. https://jmmm.material.chula.ac.th/index.php/jmmm/article/view/254.