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@article{DE_1974_10_12_a2, author = {N. I. Vulpe and K. S. Sibirskii}, title = {Affine classification of a quadratic system}, journal = {Differencialʹnye uravneni\^a}, pages = {2111--2124}, publisher = {mathdoc}, volume = {10}, number = {12}, year = {1974}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1974_10_12_a2/} }
N. I. Vulpe; K. S. Sibirskii. Affine classification of a quadratic system. Differencialʹnye uravneniâ, Tome 10 (1974) no. 12, pp. 2111-2124. http://geodesic.mathdoc.fr/item/DE_1974_10_12_a2/