@book { Verkehrsmarketing,
    title = "Verkehrsmarketing",
    author = "Christoph {Marzi}",
    year = "1999",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832413491",
    url = "https://m.diplom.de/document/217032"
}