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@article{DE_1986_22_3_a24, author = {S. A. Mazanik}, title = {The structure of the approximation function for a linear differential equation}, journal = {Differencialʹnye uravneni\^a}, pages = {542--545}, publisher = {mathdoc}, volume = {22}, number = {3}, year = {1986}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1986_22_3_a24/} }
S. A. Mazanik. The structure of the approximation function for a linear differential equation. Differencialʹnye uravneniâ, Tome 22 (1986) no. 3, pp. 542-545. http://geodesic.mathdoc.fr/item/DE_1986_22_3_a24/