@book { DasgroehumboldtBridgeBuch,
    title = "Das große humboldt Bridge-Buch",
    author = "Wolfgang {Voigt} and Karl {Ritz} and Wilhelm {Gromöller}",
    year = "2010",
    publisher = "humboldt",
    address = "Hannover, Deutschland",
    url = "https://schluetersche.openpublishing.com/document/403488"
}