@book { YieldManagementbeiFluglinien,
    title = "Yield Management bei Fluglinien",
    author = "Simone {Ungerath}",
    year = "2003",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783638184908",
    url = "https://www.hausarbeiten.de/document/12673"
}