%0 Journal Article %A V. Ya. Sikiryavyi %T On the theory of boundary value problems for equations with an operator of pseudospherical differentiation %J Trudy Matematicheskogo Instituta imeni V.A. Steklova %D 1971 %V 26 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/RM_1971_26_4_a17/ %G ru %F RM_1971_26_4_a17