@book { HistorischeWechselkursezwischenHamburgundLondon,
    title = "Historische Wechselkurse zwischen Hamburg und London",
    author = "Andreas {Gülle}",
    year = "2001",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832438111",
    url = "https://m.diplom.de/document/219488"
}