@article{TM_1985_172_a24,
     author = {P. L. Ul'yanov},
     title = {Superpositions of functions, and {Fourier} coefficients},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {338--348},
     publisher = {mathdoc},
     volume = {172},
     year = {1985},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_1985_172_a24/}
}