Danish , F. ., S. Rizvi, M. K. . Sharma, S. . Dwivedi, B. . Kumar, and S. . Kumar. “A MATHEMATICAL PROGRAMMING APPROACH IN OPTIMUM STRATIFICATION UNDER NEYMAN ALLOCATION FOR TWO STRATIFYING VARIABLES”. Journal of Reliability and Statistical Studies, vol. 12, no. 02, Dec. 2019, pp. 173-85, doi:10.13052/jrss2229-5666.12213.