@article{JRAM_1955__194_150291,
     author = {H. Rohrbach and B. Volkmann},
     title = {Verallgemeinerte asymptotische {Dichten.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {195--209},
     publisher = {mathdoc},
     volume = {194},
     year = {1955},
     zbl = {0064.28003},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1955__194_150291/}
}