United States. Bureau of the Budget and United States. Office of Management and Budget. "Explanatory Note Relating to the Summary Tables," in United States. Bureau of the Budget and United States. Office of Management and Budget. "Fiscal Year 1973," Budget of the United States Government (January 24, 1972) : 491-491. https://fraser.stlouisfed.org/title/54/item/19027/toc/420453 , accessed on May 13, 2024.