@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/