@article{MZM_1984_35_3_a6,
     author = {V. N. Konovalov},
     title = {Estimates of {Kolmogorov-type} widths for classes of differentiable periodic functions},
     journal = {Matemati\v{c}eskie zametki},
     pages = {369--380},
     publisher = {mathdoc},
     volume = {35},
     number = {3},
     year = {1984},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1984_35_3_a6/}
}