@book { Philosophiapracticauniversalis,
    title = "Philosophia practica universalis",
    subtitle = "Festgabe für Johann Mader zum 70. Geburtstag",
    author = "Helmuth {Vetter} and Konrad Paul {Liessmann}",
    year = "1996",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1083991"
}