@article{GDZPPN00230189X, title = {Functional Equations of Modular Forms.}, journal = {Mathematische Annalen}, volume = {180}, year = {1969}, pages = {337-340}, zbl = {0191.38102}, url = {http://dml.mathdoc.fr/item/GDZPPN00230189X} }
OGG, A.P. Functional Equations of Modular Forms.. Mathematische Annalen, Tome 180 (1969) pp. 337-340. http://gdmltest.u-ga.fr/item/GDZPPN00230189X/