@article{IVM_1978_10_a8,
     author = {A. I. Pulatov},
     title = {A~criterion for the orthogonality of a~system of trigonometric polynomials},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {56--60},
     publisher = {mathdoc},
     number = {10},
     year = {1978},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1978_10_a8/}
}