@book{heuser,
    title = {Gew{\"o}hnliche Differentialgleichungen},
    subtitle = {Einf{\"u}hrung in Lehre und Gebrauch},
    series = {Mathematische Leitfäden},
    author = {Heuser, Harro},
    year = {2009},
    edition = {6},
    publisher = {Vieweg+Teubner Verlag},
    isbn = {978-3-8348-0705-2}
}

@book{grune,
    title = {Gew{\"o}hnliche Differentialgleichungen},
    subtitle = {Eine Einführung aus der Perspektive der dynamischen Systeme},
    author = {Gr{\"u}ne, Lars and Junge, Oliver},
    year = {2009},
    publisher = {Vieweg+Teubner Verlag},
    series = {Bachelorkurs Mathematik},
    isbn = {978-3-8348-9261-4}
}