@book { ZurFreiheitberufen,
    title = "Zur Freiheit berufen",
    subtitle = "Zur Dimension des Ethischen im Marchtaler Plan",
    author = "Berthold {Saup}",
    year = "1995",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1115157"
}