@article{UM_2013__21_3_a2,
     author = {Calda, Emil},
     title = {Jak se tak\'e d\'a poznat pravo\'uhl\'y troj\'uheln{\'\i}k},
     journal = {U\v{c}itel matematiky},
     pages = {159--161},
     publisher = {mathdoc},
     volume = {21},
     number = {3},
     year = {2013},
     language = {cz},
     url = {http://geodesic.mathdoc.fr/item/UM_2013__21_3_a2/}
}