@book { DieGrenzedesSozialismusinDeutschland,
    title = "Die Grenze des Sozialismus in Deutschland",
    author = "Klaus {Schroeder} and Jochen {Staadt}",
    year = "2019",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b13084",
    url = "https://www.peterlang.com/document/1110369"
}