@article{TM_1967_88_a2,
     author = {S. B. Stechkin and S. A. Telyakovskii},
     title = {The approximation of differentiable functions by trigonometric polynomials in the $L$~metric},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {20--29},
     publisher = {mathdoc},
     volume = {88},
     year = {1967},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_1967_88_a2/}
}