@article{IM_1989__97_2_143702,
     author = {James Arthur},
     title = {The {L2-Lefschetz} numbers of {Hecke} operators.},
     journal = {Inventiones mathematicae},
     pages = {257--290},
     year = {1989},
     volume = {97},
     number = {2},
     zbl = {0692.22004},
     url = {http://geodesic.mathdoc.fr/item/IM_1989__97_2_143702/}
}