@article{DAN_1980_251_2_a4,
     author = {S. V. Konyagin},
     title = {On approximation properties of closed sets in {Banach} spaces and the characterization of strongly convex spaces},
     journal = {Doklady Akademii Nauk},
     pages = {276--280},
     publisher = {mathdoc},
     volume = {251},
     number = {2},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1980_251_2_a4/}
}