@article{DAN_1961_141_5_a11,
     author = {P. L. Ul'yanov},
     title = {Exact {Weyl} factors for unconditional convergence},
     journal = {Doklady Akademii Nauk},
     pages = {1048--1049},
     publisher = {mathdoc},
     volume = {141},
     number = {5},
     year = {1961},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1961_141_5_a11/}
}