@article{10_21136_CPM_1963_117470,
     author = {Pol\'akov\'a, Nad\v{e}\v{z}da},
     title = {Pozn\'amka o charakteristik\'ach uspo\v{r}\'adan\'ych mno\v{z}in},
     journal = {\v{C}asopis pro p\v{e}stov\'an{\'\i} matematiky},
     pages = {387--390},
     publisher = {mathdoc},
     volume = {088},
     number = {4},
     year = {1963},
     doi = {10.21136/CPM.1963.117470},
     mrnumber = {0180506},
     zbl = {0129.01207},
     language = {cs},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CPM.1963.117470/}
}