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@article{DAN_1957_116_6_a1, author = {N. N. Vakhania}, title = {A boundary problem for a hyperbolic system equivalent to the string vibration equation}, journal = {Doklady Akademii Nauk}, pages = {906--909}, publisher = {mathdoc}, volume = {116}, number = {6}, year = {1957}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1957_116_6_a1/} }
N. N. Vakhania. A boundary problem for a hyperbolic system equivalent to the string vibration equation. Doklady Akademii Nauk, Tome 116 (1957) no. 6, pp. 906-909. http://geodesic.mathdoc.fr/item/DAN_1957_116_6_a1/