@article{MZM_1970_8_5_a4,
     author = {V. F. Gaposhkin},
     title = {The order of approximation by partial sums of lacunary series in {Banach} spaces},
     journal = {Matemati\v{c}eskie zametki},
     pages = {575--582},
     publisher = {mathdoc},
     volume = {8},
     number = {5},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1970_8_5_a4/}
}