@article{JRAM_1959__201_150389,
     author = {Hans Rohrbach and Robert E. Clark},
     title = {Zur {Theorie} der asymptotischen {Dichte.} {II.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {113--118},
     publisher = {mathdoc},
     volume = {201},
     year = {1959},
     zbl = {0088.25601},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1959__201_150389/}
}