@book { SchuleimVereinigungsproze,
    title = "Schule im Vereinigungsprozeß",
    author = "Klaus {Riedel} and Martin {Griwatz} and Hans {Leutert} and Jürgen {Westphal}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1114530"
}