@article{SM_2012_203_3_a2,
     author = {M. G. Grigoryan},
     title = {Modifications of functions, {Fourier} coefficients and nonlinear approximation},
     journal = {Sbornik. Mathematics},
     pages = {351--379},
     year = {2012},
     volume = {203},
     number = {3},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2012_203_3_a2/}
}