@article{PMFA_1973_18_1_a3,
     author = {Grygar, Ji\v{r}{\'\i}},
     title = {Rud\'y posuv v astronomii},
     journal = {Pokroky matematiky, fyziky a astronomie},
     pages = {18--26},
     year = {1973},
     volume = {18},
     number = {1},
     language = {cs},
     url = {http://geodesic.mathdoc.fr/item/PMFA_1973_18_1_a3/}
}