@article{DAN_1971_199_3_a9,
     author = {N. K. Nikol'skii},
     title = {Spectral analysis on the unitary spectrum. {The} point spectrum},
     journal = {Doklady Akademii Nauk},
     pages = {544--547},
     publisher = {mathdoc},
     volume = {199},
     number = {3},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1971_199_3_a9/}
}