@book { JugendundIdentitt,
    title = "Jugend und Identität",
    author = "Daniel {Müller}",
    year = "2005",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832488239",
    url = "https://m.diplom.de/document/224003"
}