Ballmann, W <br/><br/>
Lectures on spaces of nonpositive curvature  with an appendix by Misha Brin, ergodicity of geodesic flows 
W. Ballmann 
 - Basel  Birkhauser-Verlag  1995 
 - vi  112 
 - DMV seminar band 25 .
<br/><br/><label>ISBN: </label>9783764352424 
<br/><br/><label>Dewey Class. No.: </label>514.7  / BAL