@book { VonPetersburgnachWeimar,
    title = "Von Petersburg nach Weimar",
    author = "Joachim {Berger} and Joachim {von Puttkamer}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1100990"
}