@article{TM_1971_112_a21,
     author = {K. I. Oskolkov},
     title = {The sharpness of the {Lebesgue} estimate for the approximation of functions with prescribed modulus of continuity by {Fourier} sums},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {337--345},
     publisher = {mathdoc},
     volume = {112},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_1971_112_a21/}
}