@book { DrachenDrachen,
    title = "Drachen! Drachen!",
    author = "Frank G. {Gerigk} and Petra {Hartmann}",
    year = "2020",
    publisher = "Blitz-Verlag",
    address = ", Deutschland",
    url = "https://tolino.openpublishing.com/document/1457886"
}