https://www.hamiltonproject.org/assets/files/UnionsEA_Web_8.19.pdf
https://www.strategie.gouv.fr/sites/strategie.gouv.fr/files/atoms/files/coe-rapport-travail-non-declare-fevrier-2019.pdf
http://uk.reuters.com/article/uk-ecb-policy-draghi-idUKKBN19H1Z7?utm_source=POLITICO.EU&utm_campaign=b1a85f2c23-EMAIL_CAMPAIGN_2017_06_27&utm_medium=email&utm_term=0_10959edeb5-b1a85f2c23-189647205