@book { KarlOtmarvonAretin,
    title = "Karl Otmar von Aretin",
    subtitle = "Historiker und Zeitgenosse",
    author = "Christof {Dipper} and Jens Ivo {Engels}",
    year = "2016",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/978-3-653-05932-8",
    url = "https://www.peterlang.com/document/1049616"
}