@article{MOMA_1981__92_178049,
     author = {H. Herold},
     title = {Nullstellen von {Real-} und {Imagin\"arteil} der {L\"osungen} linearer {Differentialgleichungen} 2. {Ordnung.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {291--298},
     publisher = {mathdoc},
     volume = {92},
     year = {1981},
     zbl = {0464.34024},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1981__92_178049/}
}