Fenchel, Werner <br/><br/>
Discontinuous groups of isometries in the hyperbolic plane  / 

 - Berlin:  Walter de Gruyter,  2003 
 - xxi, 364p. Bibl. Index. 
 - De Gruyter studies in Mathematics ; 29 .
<br/><br/><label>ISBN: </label>3110175266 
<br/><br/><label>Dewey Class. No.: </label>516  / F331.DG