United States. Bureau of the Budget and United States. Office of Management and Budget. "Budget Authority Available Through Current Action by Congress," in United States. Bureau of the Budget and United States. Office of Management and Budget. "Fiscal Year 1971," Budget of the United States Government (February 2, 1970) : 536-536. https://fraser.stlouisfed.org/title/54/item/19025/toc/62069 , accessed on April 24, 2024.