@article{MZ_1929__29_168089,
     author = {Heinrich Liebmann},
     title = {Die {Integralkurven} der {Clairautschen} {Differentialgleichung.}},
     journal = {Mathematische Zeitschrift},
     pages = {487--492},
     publisher = {mathdoc},
     volume = {29},
     year = {1929},
     zbl = {55.0252.03},
     url = {http://geodesic.mathdoc.fr/item/MZ_1929__29_168089/}
}