@article{SM_2010_201_12_a5,
     author = {V. V. Lebedev},
     title = {Quantitative estimates in {Beurling-Helson} type theorems},
     journal = {Sbornik. Mathematics},
     pages = {1811--1836},
     publisher = {mathdoc},
     volume = {201},
     number = {12},
     year = {2010},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2010_201_12_a5/}
}