@book { WorkshopWildtierfotografievordereigenenHaustr,
    title = "Workshop Wildtierfotografie vor der eigenen Haustür",
    author = "Mario {Müller}",
    year = "2021",
    publisher = "humboldt",
    address = "Hannover, Deutschland",
    url = "https://schluetersche.openpublishing.com/document/1108915"
}