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@article{DAN_1996_346_5_a3, author = {L. Z. Fishman}, title = {On the preservation of the properties of differential equations}, journal = {Doklady Akademii Nauk}, pages = {594--596}, publisher = {mathdoc}, volume = {346}, number = {5}, year = {1996}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1996_346_5_a3/} }
L. Z. Fishman. On the preservation of the properties of differential equations. Doklady Akademii Nauk, Tome 346 (1996) no. 5, pp. 594-596. http://geodesic.mathdoc.fr/item/DAN_1996_346_5_a3/