Thangjai, W., S.-A. Niwitpong, and S. Niwitpong. “Simultaneous Confidence Intervals for All Differences of Coefficients of Variation of Normal Distributions with an Application to PM2.5 Dispersion”. Thailand Statistician, vol. 20, no. 1, Dec. 2021, pp. 207-26, https://ph02.tci-thaijo.org/index.php/thaistat/article/view/245860.