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@article{DE_1971_7_9_a24, author = {L. P. Cherenkova}, title = {The simultaneity of systems of two differential equations}, journal = {Differencialʹnye uravneni\^a}, pages = {1723--1726}, publisher = {mathdoc}, volume = {7}, number = {9}, year = {1971}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1971_7_9_a24/} }
L. P. Cherenkova. The simultaneity of systems of two differential equations. Differencialʹnye uravneniâ, Tome 7 (1971) no. 9, pp. 1723-1726. http://geodesic.mathdoc.fr/item/DE_1971_7_9_a24/