%0 Journal Article %A N. V. Kislov %T A boundary value problem for a second order operator-differential equation of the type of the Tricomi equation %J Differencialʹnye uravneniâ %D 1975 %P 718-726 %V 11 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1975_11_4_a14/ %G ru %F DE_1975_11_4_a14