@article{1183532639,
author = {Solazzi, Robert E.},
title = {Isomorphism theory of congruence groups},
journal = {Bull. Amer. Math. Soc.},
volume = {77},
number = {6},
year = {1971},
pages = { 164-168},
language = {en},
url = {http://dml.mathdoc.fr/item/1183532639}
}
Solazzi, Robert E. Isomorphism theory of congruence groups. Bull. Amer. Math. Soc., Tome 77 (1971) no. 6, pp. 164-168. http://gdmltest.u-ga.fr/item/1183532639/