Magnus, Wilhelm <br/><br/>
Combinatorial group theory  Presentations of groups in terms of generators and relations 

 - 2nd rev. ed. 
 - New York  Dover  1966 
 - x,444p.  23 cm. 
<br/><br/><label>ISBN: </label>0486632814 
<br/><br/><label>Dewey Class. No.: </label>512.22,D,mag  / _