@book { QualittsmanagementimWellnessundGesundheitstourismus,
    title = "Qualitätsmanagement im Wellness- und Gesundheitstourismus",
    author = "Sandra {Ziegler}",
    year = "2010",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783842802735",
    url = "https://m.diplom.de/document/227958"
}