@article{GDZPPN002089432,
title = {The Group of Automorphisms of the Modular Function Field.},
journal = {Inventiones mathematicae},
volume = {14},
year = {1971},
pages = {253-254},
zbl = {0219.14018},
url = {http://dml.mathdoc.fr/item/GDZPPN002089432}
}
Lang, Serge. The Group of Automorphisms of the Modular Function Field.. Inventiones mathematicae, Tome 14 (1971) pp. 253-254. http://gdmltest.u-ga.fr/item/GDZPPN002089432/