%0 Journal Article %A V. N. Gol'dberg %T Convergence of the solution of a mixed problem for a hyperbolic system on the plane with singularly perturbed boundary condition to the solution of a degenerate %J Differencialʹnye uravneniâ %D 1981 %P 286-300 %V 17 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1981_17_2_a10/ %G ru %F DE_1981_17_2_a10