@article{IM2_1982_18_2_a1,
     author = {N. P. Korneichuk},
     title = {Widths in $L_p$ of classes of continuous and of differentiable functions, and optimal methods of coding and recovering functions and their derivatives},
     journal = {Izvestiya. Mathematics },
     pages = {227--247},
     publisher = {mathdoc},
     volume = {18},
     number = {2},
     year = {1982},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1982_18_2_a1/}
}