@article{ASENS_1971_4_4_3_409_0, author = {Harder, G.}, title = {A {Gauss-Bonnet} formula for discrete arithmetically defined groups}, journal = {Annales scientifiques de l'\'Ecole Normale Sup\'erieure}, pages = {409--455}, publisher = {Elsevier}, volume = {Ser. 4, 4}, number = {3}, year = {1971}, doi = {10.24033/asens.1217}, zbl = {0232.20088}, mrnumber = {46 #8255}, language = {en}, url = {http://www.numdam.org/articles/10.24033/asens.1217/} }