References
- Birnbaum , A. and Healy , W.C. 1960 . Estimates with prescribed variance based on two-stage sampling . Annals of Mathematical Statistics , 31 : 662 – 676 .
- Samuel , E. 1966 . Estimators with prescribed bound on the variance for the parameters in the Binomial and Poisson distribution, based on two-stage sampling . Journal of the American Statistical Association , 61 : 220 – 227 .