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@article{TM_1992_194_a13, author = {I. V. Petrova}, title = {Approximation on a~hyperboloid in the $L_2$-metric}, journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova}, pages = {215--228}, publisher = {mathdoc}, volume = {194}, year = {1992}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/TM_1992_194_a13/} }
I. V. Petrova. Approximation on a~hyperboloid in the $L_2$-metric. Trudy Matematicheskogo Instituta imeni V.A. Steklova, Investigations in the theory of differentiable functions of many variables and its applications. Part 14, Tome 194 (1992), pp. 215-228. http://geodesic.mathdoc.fr/item/TM_1992_194_a13/