%0 Journal Article %A A. P. Karmazin %T Parabolicity and Hyperbolicity Conditions for Boundary Elements of Surfaces %J Matematičeskie zametki %D 2001 %P 948-951 %V 70 %N 6 %I mathdoc %U http://geodesic.mathdoc.fr/item/MZM_2001_70_6_a12/ %G ru %F MZM_2001_70_6_a12