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@article{FAA_1977_11_2_a5, author = {M. A. Rvachev}, title = {A problem of {Ulam} type}, journal = {Funkcionalʹnyj analiz i ego prilo\v{z}eni\^a}, pages = {58--66}, publisher = {mathdoc}, volume = {11}, number = {2}, year = {1977}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/FAA_1977_11_2_a5/} }
M. A. Rvachev. A problem of Ulam type. Funkcionalʹnyj analiz i ego priloženiâ, Tome 11 (1977) no. 2, pp. 58-66. http://geodesic.mathdoc.fr/item/FAA_1977_11_2_a5/