@article{DAN_1980_253_6_a7,
     author = {R. S. Sadyrkhanov},
     title = {A covering map criterion in domains of normed spaces},
     journal = {Doklady Akademii Nauk},
     pages = {1318--1322},
     publisher = {mathdoc},
     volume = {253},
     number = {6},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1980_253_6_a7/}
}