@book { ControllinginderKommunalverwaltung,
    title = "Controlling in der Kommunalverwaltung",
    author = "Hans-Hermann {Kopmann}",
    year = "1997",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832401795",
    url = "https://m.diplom.de/document/216129"
}