@article{1029003553, author = {Efrat, Isaac}, title = {On the automorphic forms of a noncongruence subgroup.}, journal = {Michigan Math. J.}, volume = {34}, number = {1}, year = {1987}, pages = { 217-226}, language = {en}, url = {http://dml.mathdoc.fr/item/1029003553} }
Efrat, Isaac. On the automorphic forms of a noncongruence subgroup.. Michigan Math. J., Tome 34 (1987) no. 1, pp. 217-226. http://gdmltest.u-ga.fr/item/1029003553/