@book { DiscountBrokerage,
    title = "Discount-Brokerage",
    subtitle = "Bestandsaufnahme und Entwicklungsperspektiven",
    author = "Christian {Oester}",
    year = "1998",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832408114",
    url = "https://m.diplom.de/document/216716"
}