@article{GDZPPN002064286, title = {Zu einem hyperbolischen Gitterpunktproblem.}, journal = {Commentarii mathematici Helvetici}, volume = {56}, year = {1981}, pages = {240-271}, zbl = {0461.10023}, url = {http://dml.mathdoc.fr/item/GDZPPN002064286} }
Thurnheer, Peter. Zu einem hyperbolischen Gitterpunktproblem.. Commentarii mathematici Helvetici, Tome 56 (1981) pp. 240-271. http://gdmltest.u-ga.fr/item/GDZPPN002064286/