@article{RM_1971_26_4_a17,
     author = {V. Ya. Sikiryavyi},
     title = {On the theory of boundary value problems for equations with an operator of pseudospherical differentiation},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     publisher = {mathdoc},
     volume = {26},
     number = {4},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/RM_1971_26_4_a17/}
}