Ballmann, Werner and Others <br/><br/>
Manifolds of nonpositive curvature   
By Werner Ballmann, Mikhael Gromov and Viktor Schroeder 
 - Boston  Birkhauser  1985 
 - iv, 263p Index 
 - Progress in Mathematics    61 .
<br/><br/>  
<br/><br/><label>Dewey Class. No.: </label>516  / B192.MN