@article{JRAM_1934__170_251678,
     author = {Ludwig Bieberbach},
     title = {Zusatz zu meiner {Arbeit} },
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {242--242},
     publisher = {mathdoc},
     volume = {170},
     year = {1934},
     zbl = {0008.20301},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1934__170_251678/}
}