@book { DuftmarketingimGastgewerbe,
    title = "Duftmarketing im Gastgewerbe",
    author = "Sophie {Siegerstetter}",
    year = "2009",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836632201",
    url = "https://m.diplom.de/document/227000"
}