@article{UM_2000_8_3_a0,
     author = {Hejn\'y, Milan and Jirotkov\'a, Darina},
     title = {\v{C}tvere\v{c}kovan\'y pap{\'\i}r, troj\'uheln{\'\i}ky a {Pickova} formule},
     journal = {U\v{c}itel matematiky},
     pages = {129--135},
     year = {2000},
     volume = {8},
     number = {3},
     language = {cs},
     url = {http://geodesic.mathdoc.fr/item/UM_2000_8_3_a0/}
}