@article{MZ_1930__31_168167,
     author = {L. Bieberbach},
     title = {\"Uber die reellen {Z\"uge} der algebraischen {Gebilde}},
     journal = {Mathematische Zeitschrift},
     pages = {161--175},
     year = {1930},
     volume = {31},
     zbl = {55.1010.01},
     url = {http://geodesic.mathdoc.fr/item/MZ_1930__31_168167/}
}