%0 Journal Article %A G. D. Karatoprakliev %T A certain class of equations of mixed type %J Differencialʹnye uravneniâ %D 1969 %P 199-205 %V 5 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1969_5_1_a15/ %G ru %F DE_1969_5_1_a15