@article{KYB_1971__7_6_a4,
     author = {Ullrich, Milan and K\v{r}epela, Josef},
     title = {Ein {Beitrag} zu {Stichprobenpl\"anen} mit mehreren {Merkmalen}},
     journal = {Kybernetika},
     pages = {--466},
     publisher = {mathdoc},
     volume = {07},
     number = {6},
     year = {1971},
     mrnumber = {0317501},
     zbl = {0256.62088},
     language = {ge},
     url = {http://geodesic.mathdoc.fr/item/KYB_1971__7_6_a4/}
}