@article{GDZPPN002352311,
title = {A Theorem of Beurling-Helson Type.},
journal = {Mathematica Scandinavica},
volume = {32},
year = {1973},
pages = {139-144},
zbl = {0271.43008},
url = {http://dml.mathdoc.fr/item/GDZPPN002352311}
}
Domar, Yngve. A Theorem of Beurling-Helson Type.. Mathematica Scandinavica, Tome 32 (1973) pp. 139-144. http://gdmltest.u-ga.fr/item/GDZPPN002352311/