@article{UM_1993_1_2_a7,
     author = {Hrub\'y, Dag and Ku\v{r}ina, Franti\v{s}ek and Tich\'a, M.},
     title = {V\'yzva ke spolupr\'aci},
     journal = {U\v{c}itel matematiky},
     pages = {21--22},
     year = {1993},
     volume = {1},
     number = {2},
     language = {cs},
     url = {http://geodesic.mathdoc.fr/item/UM_1993_1_2_a7/}
}