@article{MET_1991__38_2_176369,
     author = {T.J. Rao and S. Sengupta and B.K. Sinha},
     title = {Some {Order} {Relations} {Between} {Selection} and {Inclusion}  {Probabilities} for {PPSWOR} {Sampling} {Scheme.}},
     journal = {Metrika},
     pages = {335--343},
     publisher = {mathdoc},
     volume = {38},
     number = {2},
     year = {1991},
     zbl = {0755.62020},
     url = {http://geodesic.mathdoc.fr/item/MET_1991__38_2_176369/}
}