https://www.socialeurope.eu/are-workers-going-to-pay-the-bill-for-putins-war
https://www.imk-boeckler.de/download-proxy-for-faust/download-pdf?url=http%3A%2F%2F217.89.182.78%3A451%2Fabfrage_digi.fau%2Fp_imk_report_159e_2020.pdf%3Fprj%3Dhbs-abfrage%26ab_dm%3D1%26ab_zeig%3D8946%26ab_diginr%3D8482
https://taxfoundation.org/flat-tax-state-income-tax-reform/
https://www.bancaditalia.it/compiti/riserve-portafoglio-rischi/cis/Presentazione_CIS_5.07.2021.pdf?language_id=1