%0 Journal Article %T Vitalii Ivanovich Berdyshev %J Trudy Instituta matematiki i mehaniki %D 2009 %P 5-14 %V 15 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/TIMM_2009_15_1_a0/ %G ru %F TIMM_2009_15_1_a0