@article{PMFA_1972__17_2_a3,
     author = {Birkhoff, Garrett},
     title = {V\'yuka v oboru v\v{e}deck\'ych v\'ypo\v{c}t\r{u}},
     journal = {Pokroky matematiky, fyziky a astronomie},
     pages = {78--81},
     publisher = {mathdoc},
     volume = {17},
     number = {2},
     year = {1972},
     language = {cz},
     url = {http://geodesic.mathdoc.fr/item/PMFA_1972__17_2_a3/}
}