%0 Journal Article %A Ya. N. Mamedov %T On some eigenvalue problems for an equation of mixed type %J Differencialʹnye uravneniâ %D 1990 %P 163-167 %V 26 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1990_26_1_a21/ %G ru %F DE_1990_26_1_a21