@article{10_21136_CPMF_1931_123950,
     author = {Petr, Karel},
     title = {Pozn\'amka k \v{c}l\'anku p. {Hlav\'a\v{c}ka}},
     journal = {\v{C}asopis pro p\v{e}stov\'an{\'\i} matematiky a fysiky},
     pages = {160--161},
     publisher = {mathdoc},
     volume = {60},
     number = {3},
     year = {1931},
     doi = {10.21136/CPMF.1931.123950},
     language = {cz},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CPMF.1931.123950/}
}