@article{TIMM_2010_16_4_a0,
     author = {V. I. Ivanov},
     title = {Direct and inverse theorems in approximation theory for periodic functions in {S.\,B.~Stechkins} papers and the development of these theorems},
     journal = {Trudy Instituta matematiki i mehaniki},
     pages = {5--17},
     publisher = {mathdoc},
     volume = {16},
     number = {4},
     year = {2010},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TIMM_2010_16_4_a0/}
}