@article{MZM_1968_4_3_a1,
     author = {A. V. Efimov},
     title = {Some estimates of the rate of summability of orthogonal series by linear means},
     journal = {Matemati\v{c}eskie zametki},
     pages = {261--268},
     publisher = {mathdoc},
     volume = {4},
     number = {3},
     year = {1968},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1968_4_3_a1/}
}