https://www.boeckler.de/pdf/p_imk_study_58_2018.pdf
https://blogs.imf.org/2019/04/10/high-debt-hampers-countries-response-to-a-fast-changing-global-economy/?utm_medium=email&utm_source=govdelivery
https://taxfoundation.org/flat-tax-state-income-tax-reform/
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwij8PLy0aH1AhVEhP0HHf7rAYwQFnoECAYQAQ&url=https%3A%2F%2Fassets.gov.ie%2F203426%2F468690ef-2b01-4d7d-a6d3-c0cbabcab3cb.pdf&usg=AOvVaw2-vnoHbS5dgbnNXNla3sLK