%0 Journal Article %A E. P. Eroshenkov %T The spectrum of the Bitsadze–Samarskiǐ problem %J Differencialʹnye uravneniâ %D 1983 %P 169-171 %V 19 %N 1 %U http://geodesic.mathdoc.fr/item/DE_1983_19_1_a24/ %G ru %F DE_1983_19_1_a24