Doktoei, Pornphimol, Yupaporn Areepong, and Saowanit Sukparungsee. “Average Run Length Approximation on a Double Exponentially Weighted Moving Average Control Chart through the Numerical Integral Equation Approach”. Thailand Statistician 22, no. 4 (September 29, 2024): 926–938. accessed December 11, 2025. https://ph02.tci-thaijo.org/index.php/thaistat/article/view/256081.