@article{MZM_1971_10_4_a0,
     author = {L. A. Balashov},
     title = {Series in the {Haar} system},
     journal = {Matemati\v{c}eskie zametki},
     pages = {369--374},
     publisher = {mathdoc},
     volume = {10},
     number = {4},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1971_10_4_a0/}
}