@article{MZM_1988_43_1_a6,
     author = {N. B. Pogosyan},
     title = {Summability to $+\infty$ of series in {Haar} subsystems},
     journal = {Matemati\v{c}eskie zametki},
     pages = {56--61},
     publisher = {mathdoc},
     volume = {43},
     number = {1},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1988_43_1_a6/}
}