@article{MAN_1929__101_159346,
     author = {H. Geppert},
     title = {Die permanenten {Wellen} in ringf\"ormigen {Kan\"alen}},
     journal = {Mathematische Annalen},
     pages = {424--445},
     publisher = {mathdoc},
     volume = {101},
     year = {1929},
     zbl = {55.0470.05},
     url = {http://geodesic.mathdoc.fr/item/MAN_1929__101_159346/}
}