TY  - BOOK
AU  - Ballmann, Werner
AU  - Gromov, Mikhael
TI  - Manifolds of nonpositive curvature
T2  - Progress in mathematics
SN  - 081763181X
U1  - 516 
PY  - 1985///
CY  - Boston
PB  - Birkhauser
KW  - Geometry
ER  -