
https://www.kauffman.org/wp-content/uploads/2019/12/CapitalReport_042519.pdf

https://files.taxfoundation.org/20211014170634/International-Tax-Competitiveness-Index-2021.pdf

https://www.propublica.org/article/how-private-nonprofits-ultrawealthy-tax-deductions-museums-foundation-art