@article{PMFA_1956_1_4_a11,
     author = {Havel, V\'aclav},
     title = {O mezi st{\'\i}nu vlastn{\'\i}ho a vr\v{z}en\'eho},
     journal = {Pokroky matematiky, fyziky a astronomie},
     pages = {417--420},
     year = {1956},
     volume = {1},
     number = {4},
     language = {cs},
     url = {http://geodesic.mathdoc.fr/item/PMFA_1956_1_4_a11/}
}