@article{DAN_1980_251_1_a8,
     author = {O. I. Kuznetsova and R. M. Trigub},
     title = {Two-sided estimates of the approximation of functions by {Riesz} and {Marcinkiewicz} means},
     journal = {Doklady Akademii Nauk},
     pages = {34--36},
     publisher = {mathdoc},
     volume = {251},
     number = {1},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1980_251_1_a8/}
}