@article{MAN_1981__258_163587,
     author = {Joachim Schwermer and Fritz Grunewald},
     title = {A {Nonvanishing} {Theorem} for the {Cuspidal} {Cohomology} of {SL2} {Over} {Imaginary} {Quadratic} {Integers.}},
     journal = {Mathematische Annalen},
     pages = {183--200},
     publisher = {mathdoc},
     volume = {258},
     year = {1981},
     zbl = {0458.20041},
     url = {http://geodesic.mathdoc.fr/item/MAN_1981__258_163587/}
}