%0 Journal Article %A V. G. Prikazchikov %T Two-Sided Estimates of Eigenvalues of an Elliptic Operator %J Differencialʹnye uravneniâ %D 2003 %P 974-981 %V 39 %N 7 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_2003_39_7_a12/ %G ru %F DE_2003_39_7_a12