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@article{DE_1985_21_10_a28, author = {S. G. Krein}, title = {Singularly perturbed linear differential equations in a {Banach} space}, journal = {Differencialʹnye uravneni\^a}, pages = {1814--1817}, publisher = {mathdoc}, volume = {21}, number = {10}, year = {1985}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1985_21_10_a28/} }
S. G. Krein. Singularly perturbed linear differential equations in a Banach space. Differencialʹnye uravneniâ, Tome 21 (1985) no. 10, pp. 1814-1817. http://geodesic.mathdoc.fr/item/DE_1985_21_10_a28/