@book { GestalttherapieGestaltberatung,
    title = "Gestalttherapie - Gestaltberatung",
    author = "Petra {Wittmann}",
    year = "2005",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832488970",
    url = "https://m.diplom.de/document/224073"
}