%0 Journal Article %A I. N. Dolgikh %A K. A. Mirzoev %T Deficiency indices and spectrum of self-adjoint extensions of some classes of differential operators %J Sbornik. Mathematics %D 2006 %P 525-546 %V 197 %N 4 %U http://geodesic.mathdoc.fr/item/SM_2006_197_4_a2/ %G en %F SM_2006_197_4_a2