@article{DAN_1980_251_1_a14,
     author = {V. A. Yudin},
     title = {Diophantine approximations in $L_2$ extremal problems},
     journal = {Doklady Akademii Nauk},
     pages = {54--57},
     publisher = {mathdoc},
     volume = {251},
     number = {1},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1980_251_1_a14/}
}