https://www.eurofound.europa.eu/sites/default/files/ef_publication/field_ef_document/ef22040en.pdf
http://uk2070.org.uk/wp-content/uploads/2020/02/UK2070-FINAL-REPORT.pdf
https://www.ceps.eu/system/files/CEPS%20-%20LINKEDIN%20study%20FINAL.pdf
https://www.ccomptes.fr/system/files/2019-07/20190716-rapport-regimes-speciaux-retraite.pdf