@book { WorkshopKreativeNaturfotografie,
    title = "Workshop Kreative Naturfotografie",
    author = "Bettina {Dittmann}",
    year = "2021",
    publisher = "humboldt",
    address = "Hannover, Deutschland",
    url = "https://schluetersche.openpublishing.com/document/1108916"
}