@book { Vorzeichenwechsel,
    title = "Vorzeichenwechsel",
    author = "Bernd {Markert} and Stefan {Fränzle} and Maik {Hosang}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1099891"
}