Singh , G. N. ., A. K. . Pandey, and A. K. . Jaiswal. “AN EFFICIENT CLASS OF CHAIN-TYPE EXPONENTIAL ESTIMATORS FOR POPULATION MEAN UNDER TWOPHASE SAMPLING SCHEME”. Journal of Reliability and Statistical Studies, vol. 12, no. 01, Mar. 2019, pp. 23-40, https://journals.riverpublishers.com/index.php/JRSS/article/view/20787.