@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},
     mrnumber = {46 #8255},
     zbl = {0232.20088},
     language = {en},
     url = {http://www.numdam.org/articles/10.24033/asens.1217/}
}