@article{PMFA_1987_32_6_a0,
     author = {Horsk\'y, Zden\v{e}k},
     title = {Janusovsk\'a tv\'a\v{r} {Newtonovy} fyziky},
     journal = {Pokroky matematiky, fyziky a astronomie},
     pages = {305--308},
     year = {1987},
     volume = {32},
     number = {6},
     language = {cs},
     url = {http://geodesic.mathdoc.fr/item/PMFA_1987_32_6_a0/}
}