%0 Journal Article %A N. N. Vakhania %T A boundary problem for a hyperbolic system equivalent to the string vibration equation %J Doklady Akademii Nauk %D 1957 %P 906-909 %V 116 %N 6 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1957_116_6_a1/ %G ru %F DAN_1957_116_6_a1