Funding for this research was provided by:
Hans Böckler Stiftung
Otto Brenner Foundation
Rosa Luxemburg Stiftung
Federal Foundation for the Reappraisal of the SED Dictatorship
Sächsisches Staatsministerium für Wissenschaft und Kunst
University of Applied Science Erfurt
University of Applied Science Zittau-Görlitz
Received: 22 March 2019
Accepted: 22 October 2020
First Online: 9 November 2020
Change Date: 5 March 2021
Change Type: Update
Change Details: The original article has been revised to include a funding note.
Ethic approval and consent to participate
: All procedures performed in studies involving human participants conformed with the ethical standards of the national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. The Ethics Committee of the Technische Universität Dresden, German, approved the present study (EK8012011), and only individuals who gave written informed consent were included as study participants.
: Not applicable.
: The authors declare that they have no competing interests.