@book { OperativeKennzahlenalsFrhwarnsystemiminternationalenHotelmanagement,
    title = "Operative Kennzahlen als Frühwarnsystem im internationalen Hotelmanagement",
    author = "Nicole {Bamberger}",
    year = "2005",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832488543",
    url = "https://m.diplom.de/document/224032"
}