Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{MAN_1971__191_162122, author = {J.S. BIRMAN}, title = {On {Siegel's} {Modular} {Group.}}, journal = {Mathematische Annalen}, pages = {59--68}, publisher = {mathdoc}, volume = {191}, year = {1971}, zbl = {0208.10601}, url = {http://geodesic.mathdoc.fr/item/MAN_1971__191_162122/} }
J.S. BIRMAN. On Siegel's Modular Group.. Mathematische Annalen, Tome 191 (1971), pp. 59-68. http://geodesic.mathdoc.fr/item/MAN_1971__191_162122/