@article{1183533891, author = {Allan, Nelo D.}, title = {Hecke rings of congruence subgroups}, journal = {Bull. Amer. Math. Soc.}, volume = {78}, number = {4}, year = {1972}, pages = { 541-545}, language = {en}, url = {http://dml.mathdoc.fr/item/1183533891} }
Allan, Nelo D. Hecke rings of congruence subgroups. Bull. Amer. Math. Soc., Tome 78 (1972) no. 4, pp. 541-545. http://gdmltest.u-ga.fr/item/1183533891/