@article{GFA_1994__4_6_58158,
     author = {P. Sarnak and R. Philips},
     title = {On {Cusp} {Forms} in {Character} {Varieties.}},
     journal = {Geometric and functional analysis},
     pages = {93--118},
     publisher = {mathdoc},
     volume = {4},
     number = {6},
     year = {1994},
     zbl = {0804.11038},
     url = {http://geodesic.mathdoc.fr/item/GFA_1994__4_6_58158/}
}