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@article{DE_1968_4_9_a11, author = {M. M. Smirnov}, title = {The first boundary value problem for a certain equation of mixed type}, journal = {Differencialʹnye uravneni\^a}, pages = {1663--1666}, publisher = {mathdoc}, volume = {4}, number = {9}, year = {1968}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1968_4_9_a11/} }
M. M. Smirnov. The first boundary value problem for a certain equation of mixed type. Differencialʹnye uravneniâ, Tome 4 (1968) no. 9, pp. 1663-1666. http://geodesic.mathdoc.fr/item/DE_1968_4_9_a11/