@book { GrundlagenBlitzfotografie,
    title = "Grundlagen Blitzfotografie",
    author = " {Fotoschule des Sehens} and Peter {Uhl} and Martina {Walther-Uhl}",
    year = "2018",
    publisher = "humboldt",
    address = "Hannover, Deutschland",
    url = "https://schluetersche.openpublishing.com/document/404138"
}