%0 Journal Article %A Yu. K. Lando %T On eigenvalues and eigenfunctions of integro-differential operators %J Differencialʹnye uravneniâ %D 1965 %P 977-989 %V 1 %N 7 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1965_1_7_a11/ %G ru %F DE_1965_1_7_a11