@article{DAN_1969_188_4_a7,
     author = {B. I. Rozenfel'd},
     title = {Principal bundles whose base spaces satisfy the second countability axiom},
     journal = {Doklady Akademii Nauk},
     pages = {758--761},
     publisher = {mathdoc},
     volume = {188},
     number = {4},
     year = {1969},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1969_188_4_a7/}
}