http://www.resolutionfoundation.org/app/uploads/2017/01/Audit-2017.pdf
https://www.taxpolicycenter.org/sites/default/files/publication/163549/report-taxing-business-incomes-evidence-from-the-survey-of-consumer-finances.pdf
https://www.courthousenews.com/eu-must-act-quickly-to-catch-up-to-us-warns-report-author/
https://www.nao.org.uk/wp-content/uploads/2018/01/PFI-and-PF2.pdf