@book { MglichkeitenundGrenzendesOutsourcingvonFoodBeverageLeistungeninderHotellerie, title = "Möglichkeiten und Grenzen des Outsourcing von Food & Beverage Leistungen in der Hotellerie", author = "Karoline {Keller}", year = "1999", publisher = "Diplom.de", address = "Hamburg, Deutschland", doi = "10.3239/9783832418236", url = "https://m.diplom.de/document/217678" }