Pongpullponsak, Adisak, Wichai Suracherkeiti, and Chaowalit Panthong. “The Economic Model of x̄ Control Chart Using Shewhart Method for Skewed Distributions”. Thailand Statistician 7, no. 1 (May 28, 2015): 81–99. accessed September 20, 2026. https://ph02.tci-thaijo.org/index.php/thaistat/article/view/34324.