@article{01625952, title = {Period functions for Maass wave forms. I.}, journal = {Annals of Mathematics. Second Series}, volume = {153}, year = {2001}, pages = {191-258}, doi = {10.2307/2661374}, zbl = {1061.11021}, language = {en}, url = {http://dml.mathdoc.fr/item/01625952} }
Lewis, J.; Zagier, D. Period functions for Maass wave forms. I.. Annals of Mathematics. Second Series, Tome 153 (2001) pp. 191-258. doi : 10.2307/2661374. http://gdmltest.u-ga.fr/item/01625952/