United States. Office of Management and Budget. "Composition of Social Insurance and Contributions and Excise Taxes," in United States. Office of Management and Budget. "Fiscal Year 1992," Historical Tables, Budget of the United States Government (February 4, 1991) : 26-30. https://fraser.stlouisfed.org/title/383/item/6418/toc/394059 , accessed on May 4, 2024.