@article{IM_1971__12_142063,
     author = {H. Petersson},
     title = {\"Uber die {Mittelwerte} der automorphen {Funktionen} und die {Nullstellen} der automorphen {Formen.}},
     journal = {Inventiones mathematicae},
     pages = {1--34},
     publisher = {mathdoc},
     volume = {12},
     year = {1971},
     zbl = {0216.04301},
     url = {http://geodesic.mathdoc.fr/item/IM_1971__12_142063/}
}