https://www.ifo.de/DocDL/EEAG-2019-executive-summary.pdf
https://www.veblen-institute.org/Editorial-Assumer-l-impot
https://www.socialeurope.eu/the-frugal-four-should-save-the-european-project
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_pb_98_2020.pdf%3Fprj%3Dhbs-abfrage%26ab_dm%3D1%26ab_zeig%3D9110%26ab_diginr%3D8482