@book { Ahnenforschung,
    title = "Ahnenforschung",
    subtitle = "Schritt für Schritt zur eigenen Familiengeschichte",
    author = "Sascha {Ziegler}",
    year = "2012",
    publisher = "humboldt",
    address = "Hannover, Deutschland",
    url = "https://schluetersche.openpublishing.com/document/403155"
}