@book { BewertungoffenerImmobilienfonds,
    title = "Bewertung offener Immobilienfonds",
    author = "Kay {Zetzsche}",
    year = "2009",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836636933",
    url = "https://m.diplom.de/document/227270"
}