@book { SprachenfreiheitimVerbrauchervertragsrecht,
    title = "Sprachenfreiheit im Verbrauchervertragsrecht",
    author = "Markus {Dreißigacker}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1094304"
}