@article{GDZPPN002462818, title = {On Efficiency of the Ratio Estimator.}, journal = {Metrika}, volume = {36}, year = {1989}, pages = {55-59}, zbl = {0677.62005}, url = {http://dml.mathdoc.fr/item/GDZPPN002462818} }
Chaudhuri, A.; Adhikary, A.K. On Efficiency of the Ratio Estimator.. Metrika, Tome 36 (1989) pp. 55-59. http://gdmltest.u-ga.fr/item/GDZPPN002462818/