@article{FAA_2002_36_1_a2,
     author = {V. V. Lebedev},
     title = {Diffeomorphisms of the {Circle} and the {Beurling--Helson} {Theorem}},
     journal = {Funkcionalʹnyj analiz i ego prilo\v{z}eni\^a},
     pages = {30--35},
     publisher = {mathdoc},
     volume = {36},
     number = {1},
     year = {2002},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FAA_2002_36_1_a2/}
}