Sury, B <br/><br/>
Congruence subgroup problem  elementary approach aimed at applications 
B. Sury 
 - New Delhi  Hindustan Book Agency  2003 
 - xv  301 
 - TRIM 24 .
<br/><br/><label>ISBN: </label>8585931380 
<br/><br/><label>Dewey Class. No.: </label>2.04  / SURY