http://www.ips-journal.eu/topics/european-union/article/show/no-more-penny-pinching-2076/
https://www.brookings.edu/articles/the-difference-in-how-the-wealthy-make-money-and-pay-taxes/
https://www.diw.de/documents/publikationen/73/diw_01.c.670904.de/19-31-3.pdf
https://www.brookings.edu/blog/up-front/2017/08/03/the-hutchins-center-explains-the-debt-limit/?utm_campaign=Brookings%20Brief&utm_source=hs_email&utm_medium=email&utm_content=54989469