@book { DasJubilumsheftMutundMarxismus,
    title = "Das Jubiläumsheft – Mut und Marxismus",
    author = "Lothar {Geisler}",
    year = "2023",
    publisher = "Neue Impulse Verlag",
    address = "Essen, Deutschland",
    url = "https://neueimpulseverlag.openpublishing.com/document/1400215"
}