Semsri, A. “Determination of Optimum Temperature of Barrel Heater forReducing Waste in Plastic Injection Molding Process of Tractor Turn Signal Cover Parts using DMAIC Techniques”. Engineering and Technology Horizons, vol. 39, no. 3, Sept. 2022, pp. 111-30, https://ph01.tci-thaijo.org/index.php/lej/article/view/248112.