วังคะฮาด ก., and คุปตัษเฐียร ณ. . “Defect Reduction in Gear Production : A Case Study of Motor Component Manufacturing”. Journal of Engineering, RMUTT, vol. 2, Dec. 2014, pp. 29-41, https://ph01.tci-thaijo.org/index.php/jermutt/article/view/242064.