@book { RealpolitikoderantibolschewistischerKreuzzug,
    title = "Realpolitik oder antibolschewistischer Kreuzzug?",
    author = "Ulrich {Kaiser}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1098270"
}