TY  - BOOK
AU  - Sury,B.
TI  - Congruence subgroup problem: An elementary approach aimed at applications
SN  - 9788185931380
U1  - 516.2,S94C 
PY  - 2003///
CY  - New Delhi
PB  - Hindustan Book Agency
KW  - Geometry, Congruences
ER  -