TY  - BOOK
AU  - Ballmann, Werner and Others
AU  - Gromov, Mikhael ; jt. auth.
AU  - Schroeder, Viktor ; jt. auth.
TI  - Manifolds of nonpositive curvature
T2  - Progress in Mathematics 
U1  - 516 
PY  - 1985///
CY  - Boston
PB  - Birkhauser
ER  -