Dr.P.K.Sivakumaran, and Mrs.T. Kanneswari. “Control Chart Based On Six Sigma For Range With Robust Scale Estimator”. Journal of Computational Analysis and Applications (JoCAAA), vol. 33, no. 08, Sept. 2024, pp. 72-81, https://eudoxuspress.com/index.php/pub/article/view/1237.