%0 Journal Article
%A A. L. Verner
%T On the extrinsic geometry of elementary complete surfaces with nonpositive curvature.~II
%J Sbornik. Mathematics
%D 1968
%P 99-123
%V 4
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/SM_1968_4_1_a6/
%G en
%F SM_1968_4_1_a6