
https://www.bertelsmann-stiftung.de/en/publications/publication/did/social-justice-in-the-eu-index-report-2016/

https://www.whitehouse.gov/wp-content/uploads/2018/10/The-Opportunity-Costs-of-Socialism.pdf

https://www.eurofound.europa.eu/sites/default/files/ef_publication/field_ef_document/ef18036en.pdf