@article{JDM_1920__29_145583,
     author = {P. Franck},
     title = {Die paraboloidischen {Fl\"achen} und ihre {Lieschen} {Paraboloide.}},
     journal = {Jahresbericht der Deutschen Mathematiker-Vereinigung},
     pages = {75--93},
     publisher = {mathdoc},
     volume = {29},
     year = {1920},
     zbl = {47.0659.03},
     url = {http://geodesic.mathdoc.fr/item/JDM_1920__29_145583/}
}