@article{SM_1981_38_4_a6,
     author = {A. A. Sahakian},
     title = {Integral moduli of smoothness and the {Fourier} coefficients of the composition of functions},
     journal = {Sbornik. Mathematics},
     pages = {549--561},
     year = {1981},
     volume = {38},
     number = {4},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1981_38_4_a6/}
}