https://www.zi-mannheim.de/fileadmin/user_upload/downloads/forschung/forschungsverbuende/MHG-Studie-Endbericht-Zusammenfassung.pdf
https://freedomhouse.org/report/freedom-net/2019/crisis-social-media
https://www.brookings.edu/articles/understanding-democratic-decline-in-the-united-states/