@book { UnterschwarzrotgoldenemBannerunddemSignumdesDoppeladlers,
    title = "Unter schwarz-rot-goldenem Banner und dem Signum des Doppeladlers",
    author = "Hans Thorald {Michaelis}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1079526"
}