@article{MZM_1971_10_5_a0,
     author = {V. A. Bolgov},
     title = {Absolute summability of orthogonal series by {Hausdorff} methods},
     journal = {Matemati\v{c}eskie zametki},
     pages = {485--492},
     publisher = {mathdoc},
     volume = {10},
     number = {5},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1971_10_5_a0/}
}