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@article{DE_1971_7_10_a16, author = {Yu. N. Bibikov}, title = {The reducibility of a system of two differential equations to normal form}, journal = {Differencialʹnye uravneni\^a}, pages = {1899--1902}, publisher = {mathdoc}, volume = {7}, number = {10}, year = {1971}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1971_7_10_a16/} }
Yu. N. Bibikov. The reducibility of a system of two differential equations to normal form. Differencialʹnye uravneniâ, Tome 7 (1971) no. 10, pp. 1899-1902. http://geodesic.mathdoc.fr/item/DE_1971_7_10_a16/