United States. Bureau of the Budget and United States. Office of Management and Budget. "Budget Receipts by Source," in United States. Bureau of the Budget and United States. Office of Management and Budget. "Fiscal Year 1970," Budget of the United States Government (January 15, 1969) : 523-523. https://fraser.stlouisfed.org/title/54/item/19024/toc/237695 , accessed on April 19, 2024.