@article{MZM_1970_8_5_a2,
     author = {V. N. Gabushin},
     title = {Best approximations of functionals on certain sets},
     journal = {Matemati\v{c}eskie zametki},
     pages = {551--562},
     publisher = {mathdoc},
     volume = {8},
     number = {5},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1970_8_5_a2/}
}