Niwitpong, Sa-aat, and Penpak Pinkoompee. “Prediction Intervals for a Single Future Value of Normal and Non-Normal Variables”. Thailand Statistician 4 (May 28, 2015): 85–92. accessed September 28, 2026. https://ph02.tci-thaijo.org/index.php/thaistat/article/view/34361.