Team, Support. “A New Ratio Estimator for Population Total in the Presence of Nonresponse under Unequal Probability Sampling Without Replacement: Chugiat Ponkaew, Nuanpan Lawson”. Thai Journal of Mathematics (December 30, 2018): 417–429. Accessed April 27, 2024. https://thaijmath2.in.cmu.ac.th/index.php/thaijmath/article/view/750.