@book { MarketinginstrumenteinderindividuellenmittelstndischenGastronomie,
    title = "Marketinginstrumente in der individuellen mittelständischen Gastronomie",
    subtitle = "Am Beispiel eines Cafés",
    author = "Sophie Elise {Aschenbeck}",
    year = "2010",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836642279",
    url = "https://m.diplom.de/document/227584"
}