https://www.socialeurope.eu/the-frugal-four-should-save-the-european-project
https://www.imf.org/-/media/Files/Publications/Fandd/Article/2022/June/Prasad.ashx
http://www.oecd.org/eco/outlook/economic-forecast-summary-united-kingdom-oecd-economic-outlook-june-2017.pdf
https://taxfoundation.org/flat-tax-state-income-tax-reform/