@article{MZ_1967__96_170690,
     author = {Hans Petersson},
     title = {\"Uber eine {Spurbildung} bei automorphen {Formen.}},
     journal = {Mathematische Zeitschrift},
     pages = {296--332},
     year = {1967},
     volume = {96},
     zbl = {0177.34902},
     url = {http://geodesic.mathdoc.fr/item/MZ_1967__96_170690/}
}