@book { InternationalisierungimMittelstand,
    title = "Internationalisierung im Mittelstand",
    author = "Nina {Günther}",
    year = "2003",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832471989",
    url = "https://m.diplom.de/document/222502"
}