@article{MZM_1981_29_2_a2, author = {V. I. Berdyshev}, title = {Variation of the norms in the problem of best approximation}, journal = {Matemati\v{c}eskie zametki}, pages = {181--196}, publisher = {mathdoc}, volume = {29}, number = {2}, year = {1981}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/MZM_1981_29_2_a2/} }