%0 Journal Article %A S. V. Buyalo %T Homotopy invariance of some geometric properties of three-dimensional manifolds of nonpositive curvature %J Algebra i analiz %D 1991 %P 93-112 %V 3 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/AA_1991_3_4_a2/ %G ru %F AA_1991_3_4_a2