@article{GDZPPN002311933, title = {Units in the Modular Function Field. I.}, journal = {Mathematische Annalen}, volume = {217}, year = {1975}, pages = {67-96}, zbl = {0311.14005}, url = {http://dml.mathdoc.fr/item/GDZPPN002311933} }
Kubert, Dan; Lang, Serge. Units in the Modular Function Field. I.. Mathematische Annalen, Tome 217 (1975) pp. 67-96. http://gdmltest.u-ga.fr/item/GDZPPN002311933/