@article{MET_1975__22_175654,
     author = {S.G. Prabhu-Afgaonkar},
     title = {On {Unordering} {Horvitz} and {Thompson's} {Tl} {-Class} of {Linear} {Estimators.}},
     journal = {Metrika},
     pages = {55--60},
     publisher = {mathdoc},
     volume = {22},
     year = {1975},
     zbl = {0302.62005},
     url = {http://geodesic.mathdoc.fr/item/MET_1975__22_175654/}
}