%0 Journal Article %A G. A. Trunov %T An estimate for a~spectral relation for incomplete factorization of the form $S^*S$ of the difference approximation of the Laplace operator in the case of a~quasiregular operator~$S$ %J Matematičeskie zametki %D 1990 %P 155-156 %V 47 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/MZM_1990_47_2_a21/ %G ru %F MZM_1990_47_2_a21