@article{MET_1970__15_175413,
     author = {S.G. Prabhu Ajgaonkar},
     title = {A {Contribution} to the {Theory} of {Unique} {Estimators} for {Horvitz} and {Thompson's} {Classes} of {Linear} {Estimators}},
     journal = {Metrika},
     pages = {40--47},
     publisher = {mathdoc},
     volume = {15},
     year = {1970},
     zbl = {0184.42304},
     url = {http://geodesic.mathdoc.fr/item/MET_1970__15_175413/}
}