@article{UM_1993__1_4_a5,
     author = {Hejn\'y, M.},
     title = {The method of suplementing a picture by drawing},
     journal = {U\v{c}itel matematiky},
     pages = {8--15},
     publisher = {mathdoc},
     volume = {01},
     number = {4},
     year = {1993},
     language = {cz},
     url = {http://geodesic.mathdoc.fr/item/UM_1993__1_4_a5/}
}