@article{DAN_1961_138_3_a15,
     author = {P. L. Ul'yanov},
     title = {Divergent series over a {Haar} system and over bases},
     journal = {Doklady Akademii Nauk},
     pages = {556--559},
     publisher = {mathdoc},
     volume = {138},
     number = {3},
     year = {1961},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1961_138_3_a15/}
}