@article{MOMA_1963__67_177230,
     author = {Hans Hornich},
     title = {Huygenssche {Differentialgleichungen} im {R2.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {433--435},
     publisher = {mathdoc},
     volume = {67},
     year = {1963},
     zbl = {0144.13901},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1963__67_177230/}
}