@book { ProduktpolitischeInnovationenamKreuzfahrtmarkt,
    title = "Produktpolitische Innovationen am Kreuzfahrtmarkt",
    author = "Anja {Perner}",
    year = "2000",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832420352",
    url = "https://m.diplom.de/document/217466"
}