%0 Journal Article %A R. K. Romanovskii %T Tests for boundedness of the solutions of a certain mixed boundary value problem for a second order hyperbolic equation in a Banach space %J Izvestiâ vysših učebnyh zavedenij. Matematika %D 1969 %P 60-66 %N 1 %U http://geodesic.mathdoc.fr/item/IVM_1969_1_a9/ %G ru %F IVM_1969_1_a9