@article{GDZPPN002443066, title = {Thetanullwerte and stable modular forms for Hecke groups.}, journal = {Mathematische Zeitschrift}, volume = {217}, year = {1994}, pages = {529-540}, zbl = {0814.11029}, url = {http://dml.mathdoc.fr/item/GDZPPN002443066} }
Manni, Riccardo Salvati. Thetanullwerte and stable modular forms for Hecke groups.. Mathematische Zeitschrift, Tome 217 (1994) pp. 529-540. http://gdmltest.u-ga.fr/item/GDZPPN002443066/