@book { Projektionssymptome,
    title = "Projektionssymptome",
    author = "Otto {Bergsmann} and Roswitha {Bergsmann}",
    year = "2021",
    publisher = "facultas",
    address = "Wien, Österreich",
    url = "https://campus-lizenzen.facultas.at/document/1102018"
}