Nuriman, Muhammad Alifian, Michael B. C. Khoo, Sajal Saha, Zhi Lin Chong, and Shanyu Chua. “Performance of the Double Sampling Coefficient of Variation Chart under Measurement Errors Using a Linear Covariate Error Model for Monitoring NPK Fertilizer Manufacturing Process”. Journal of Quality Measurement and Analysis 22, no. 1 (March 26, 2026): 173–204. Accessed August 17, 2026. https://jqma.ukm.my/index.php/jqma/article/view/155.