@article{CMUC_1991__32_4_a15,
     author = {Matou\v{s}ek, Ji\v{r}{\'\i} and Loebl, Martin},
     title = {Hercules versus {Hidden} {Hydra} {Helper}},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {731--741},
     publisher = {mathdoc},
     volume = {32},
     number = {4},
     year = {1991},
     mrnumber = {1159820},
     zbl = {0763.05029},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1991__32_4_a15/}
}