@book { KartengesttzteZahlungssysteme,
    title = "Kartengestützte Zahlungssysteme",
    author = "Katharina {Schaufelberger}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Lausanne, Switzerland",
    url = "https://www.peterlang.com/document/1116973"
}