@article{IM2_1995_45_2_a7,
     author = {V. T. Shevaldin},
     title = {Lower estimates of the widths of the classes of functions defined by a modulus of continuity},
     journal = {Izvestiya. Mathematics},
     pages = {399--415},
     year = {1995},
     volume = {45},
     number = {2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1995_45_2_a7/}
}