Bhushan, S. ., A. . Pandey, and S. . Katara. “A CLASS OF ESTIMATORS IN DOUBLE SAMPLING USING TWO AUXILIARY VARIABLES”. Journal of Reliability and Statistical Studies, vol. 1, no. 1, Dec. 2008, pp. 67-73, https://journals.riverpublishers.com/index.php/JRSS/article/view/22119.