@misc{PMFA_1959_4_1_a17,
     title = {Optick\'a pozorov\'an{\'\i} um\v{e}l\'ych dru\v{z}ic {Zem\v{e}} [obr\'azky]},
     journal = {Pokroky matematiky, fyziky a astronomie},
     pages = {143},
     year = {1959},
     volume = {4},
     number = {1},
     language = {cs},
     url = {http://geodesic.mathdoc.fr/item/PMFA_1959_4_1_a17/}
}