Ismail, Muhammad, Nazia Kawnal, and Muhammad Q. Shahbaz. “Generalized Ratio-Product-Type Estimator for Variance Using Auxiliary Information in Simple Random Sampling”. Kuwait Journal of Science 45, no. 1 (January 24, 2018). Accessed April 25, 2026. https://journalskuwait.org/kjs/index.php/KJS/article/view/1727.