@article{MZ_1929__29_168092,
     author = {J. Popken},
     title = {Zur {Tranzendenz} von ....},
     journal = {Mathematische Zeitschrift},
     pages = {542--548},
     publisher = {mathdoc},
     volume = {29},
     year = {1929},
     language = {de},
     url = {http://geodesic.mathdoc.fr/item/MZ_1929__29_168092/}
}