@article{PMFA_2007__52_2_a4,
     author = {Verstraelen, Leopold},
     title = {Univerz\'aln{\'\i} p\v{r}{\'\i}rodn{\'\i} tvary},
     journal = {Pokroky matematiky, fyziky a astronomie},
     pages = {142--151},
     publisher = {mathdoc},
     volume = {52},
     number = {2},
     year = {2007},
     zbl = {1265.53006},
     language = {cz},
     url = {https://geodesic-test.mathdoc.fr/item/PMFA_2007__52_2_a4/}
}