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@article{DE_1971_7_8_a7, author = {V. L. Lubih}, title = {The existence of a local invariant surface in the absence of linear approximation}, journal = {Differencialʹnye uravneni\^a}, pages = {1410--1418}, publisher = {mathdoc}, volume = {7}, number = {8}, year = {1971}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1971_7_8_a7/} }
V. L. Lubih. The existence of a local invariant surface in the absence of linear approximation. Differencialʹnye uravneniâ, Tome 7 (1971) no. 8, pp. 1410-1418. http://geodesic.mathdoc.fr/item/DE_1971_7_8_a7/