@article{PMFA_2009_54_4_a6,
     author = {Hadrava, Petr and Hadravov\'a, Alena},
     title = {Antick\'y p\v{r}edch\r{u}dce st\v{r}edov\v{e}k\'ych orloj\r{u}?},
     journal = {Pokroky matematiky, fyziky a astronomie},
     pages = {318--324},
     year = {2009},
     volume = {54},
     number = {4},
     language = {cs},
     url = {http://geodesic.mathdoc.fr/item/PMFA_2009_54_4_a6/}
}