@book { WhrungsunionundEuropischeZentralbank,
    title = "Währungsunion und Europäische Zentralbank",
    author = "Heidi {Lorenz}",
    year = "1997",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832405014",
    url = "https://m.diplom.de/document/216218"
}