@article{TIMM_2001_7_1_a2,
     author = {A. G. Babenko},
     title = {On the {Jackson{\textendash}Stechkin} inequality for the best $L^2$-approximations of functions by trigonometric polynomials},
     journal = {Trudy Instituta matematiki i mehaniki},
     pages = {30--46},
     year = {2001},
     volume = {7},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TIMM_2001_7_1_a2/}
}