United States. Bureau of the Budget and United States. Office of Management and Budget. "Summary of Major Trust Fund Balances Available at Start of Year," in United States. Bureau of the Budget and United States. Office of Management and Budget. "Fiscal Year Ending June 30, 1960," Budget of the United States Government (January 19, 1959) : 963-963. https://fraser.stlouisfed.org/title/54/item/19013/toc/83102 , accessed on April 25, 2024.