@book { DieumsatzsteuerlicheBehandlungvonReiseninReihengeschften,
    title = "Die umsatzsteuerliche Behandlung von Reisen in Reihengeschäften",
    author = "Robert {Morgner}",
    year = "2008",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836610629",
    url = "https://m.diplom.de/document/225636"
}