TY  - JOUR
AU  - Robert Bieri
TI  - A 1 1/2-dimensional version of Hopf's Theorem on the number of ends of a group.
JO  - Commentarii mathematici Helvetici
PY  - 1982
SP  - 25
EP  - 40
VL  - 57
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/CMH_1982__57_139893/
ID  - CMH_1982__57_139893
ER  -