https://www.whitehouse.gov/wp-content/uploads/2021/05/budget_fy22.pdf
https://taxfoundation.org/flat-tax-state-income-tax-reform/
https://www.crfb.org/blogs/whats-latest-build-back-better-framework
https://www.bruegel.org/wp-content/uploads/2022/04/PC-06-1.pdf