@article{RM_1967_22_1_a19,
     author = {V. F. Gaposhkin},
     title = {Systems of the form $\{\varphi_k(n_k{x})\}$ equivalent to systems of independent functions},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     year = {1967},
     volume = {22},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/RM_1967_22_1_a19/}
}