@book { Fremdsprachenunterricht,
    title = "Fremdsprachenunterricht",
    subtitle = "Zur systemischen Analyse didaktischer Interaktion",
    author = "Bettina {Paris}",
    year = "1998",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1086637"
}