Ahuja, T. K. ., P. . Misra, and O. K. . Belwal. “A Generalized Two Phase Sampling Estimator of Ratio of Population Means Using Auxiliary Information”. Journal of Reliability and Statistical Studies, vol. 14, no. 01, Mar. 2021, pp. 1-16, doi:10.13052/jrss0974-8024.1411.