@article{IVM_1982_1_a14,
     author = {V. Yu. Popov},
     title = {Sharp inequalities for best mean square approximations in a~space of {Bessel} potentials},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {83--86},
     publisher = {mathdoc},
     number = {1},
     year = {1982},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1982_1_a14/}
}