@article{DAN_1971_200_4_a3,
     author = {L. M. Kuperman and Yu. M. Repin},
     title = {On controllability in infinite-dimensional spaces},
     journal = {Doklady Akademii Nauk},
     pages = {767--769},
     publisher = {mathdoc},
     volume = {200},
     number = {4},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1971_200_4_a3/}
}