@article{TIMM_2018_24_4_a13,
     author = {N. A. Il'yasov},
     title = {On the equivalence of some relations in different metrics between norms, best approximations, and moduli of smoothness of periodic functions and their derivatives},
     journal = {Trudy Instituta matematiki i mehaniki},
     pages = {176--188},
     year = {2018},
     volume = {24},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TIMM_2018_24_4_a13/}
}