@article{UM_2020_28_4_a3,
     author = {Ku\v{r}ina, Franti\v{s}ek},
     title = {Jak to vlastn\v{e} je? {Troj\'uheln{\'\i}k}},
     journal = {U\v{c}itel matematiky},
     pages = {222--233},
     year = {2020},
     volume = {28},
     number = {4},
     language = {cs},
     url = {http://geodesic.mathdoc.fr/item/UM_2020_28_4_a3/}
}