@book { DasgroeRudolfSteinerBuch,
    title = "Das große Rudolf-Steiner-Buch",
    author = "Axel {Burkart}",
    year = "2012",
    publisher = "dotbooks Verlag",
    address = "München, Deutschland",
    doi = "10.3239/9783943835953",
    url = "https://m.dotbooks.de/document/199278"
}