%0 Journal Article
%A Robert Bieri
%T A 1 1/2-dimensional version of Hopf's Theorem on the number of ends of a group.
%J Commentarii mathematici Helvetici
%D 1982
%P 25-40
%V 57
%I mathdoc
%U http://geodesic.mathdoc.fr/item/CMH_1982__57_139893/
%F CMH_1982__57_139893