@book { Digitalfotografie,
    title = "Digitalfotografie",
    subtitle = "Das große Einsteigerbuch",
    author = "Rainer {Emling}",
    year = "2010",
    publisher = "humboldt",
    address = "Hannover, Deutschland",
    url = "https://schluetersche.openpublishing.com/document/403416"
}