@article{PMFA_1959_4_4_a1,
     author = {Boltyanskij, V.G. and Yefremovich, V. A.},
     title = {O topologii. {II}},
     journal = {Pokroky matematiky, fyziky a astronomie},
     pages = {394--421},
     year = {1959},
     volume = {4},
     number = {4},
     zbl = {0229.54002},
     language = {cs},
     url = {http://geodesic.mathdoc.fr/item/PMFA_1959_4_4_a1/}
}