@article{IVM_1969_12_a14,
     author = {M. A. Yastrebova},
     title = {The $(C,\,1)$-summability of the expansions of functions in periodic multiplicative orthonormal systems},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {112--123},
     year = {1969},
     number = {12},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1969_12_a14/}
}