TY  - JOUR
AU  - G. Harder
TI  - A Gauss--Bonnet formula for discrete arithmetically defined groups
JO  - Matematika
PY  - 1974
SP  - 20
EP  - 55
VL  - 18
IS  - 6
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MAT_1974_18_6_a1/
LA  - ru
ID  - MAT_1974_18_6_a1
ER  -