@book { Gestalttherapie,
    title = "Gestalttherapie",
    author = "Viola {Düben}",
    year = "1997",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832401498",
    url = "https://m.diplom.de/document/216101"
}