%0 Journal Article %A R. Bayramov %T Nonselfadjoint quadratic operator pencils and elliptic problems %J Differencialʹnye uravneniâ %D 1998 %P 559-561 %V 34 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1998_34_4_a17/ %G ru %F DE_1998_34_4_a17