United States. Department of the Treasury. "District of Columbia School Teachers' Retirement Act," in United States. Department of the Treasury. "Annual Report of the Secretary of the Treasury on the State of the Finances for the Fiscal Year Ended June 30, 1920, with Appendices," Annual Report of the Secretary of the Treasury on the State of the Finances (Fiscal Year Ended June 30, 1920) : 226-227. https://fraser.stlouisfed.org/title/194/item/5566/toc/284280 , accessed on April 24, 2024.