@book { MarthasGeheimnis,
    title = "Marthas Geheimnis",
    subtitle = "Roman",
    author = "Brigitte {Aubert} and Eliane {Hagedorn} and Barbara {Reitz}",
    year = "2017",
    publisher = "dotbooks Verlag",
    address = "München, Deutschland",
    url = "https://www.dotbooks.de/document/371152"
}