@book { DasGeheimnisdesKetzersTeil4,
    title = "Das Geheimnis des Ketzers - Teil 4",
    author = "Mattias {Gerwald}",
    year = "2015",
    publisher = "dotbooks Verlag",
    address = "München, Deutschland",
    url = "https://m.dotbooks.de/document/310768"
}