@article{RMF_2007_82_3_a7,
     author = {Calda, Emil},
     title = {Jednotkov\'y \v{c}tverec a \v{c}ty\v{r}i obd\'eln{\'\i}ky t\'eho\v{z} obsahu},
     journal = {Rozhledy matematicko-fyzik\'aln{\'\i}},
     pages = {50--52},
     year = {2007},
     volume = {82},
     number = {3},
     language = {cs},
     url = {http://geodesic.mathdoc.fr/item/RMF_2007_82_3_a7/}
}