@article{MZM_1993_53_2_a18,
     author = {V. T. Shevaldin},
     title = {Lower bounds for the widths of classes of periodic functions with a~bounded fractional derivative},
     journal = {Matemati\v{c}eskie zametki},
     pages = {145--151},
     publisher = {mathdoc},
     volume = {53},
     number = {2},
     year = {1993},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1993_53_2_a18/}
}