@book { PricingandYieldManagement,
    title = "Pricing and Yield-Management",
    author = "Christian {Stahr} and J. Zhang {H. Wypior, L. Zhang}",
    year = "2007",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783638037440",
    url = "https://www.hausarbeiten.de/document/82878"
}