United States. Department of the Treasury. "Bill Offering, February 1, 1971," in United States. Department of the Treasury. "Volume 172," Press Releases of the United States Department of the Treasury (February 1, 1971 - March 31, 1971) : 29-30. https://fraser.stlouisfed.org/title/6111/item/587015/toc/542102 , accessed on March 29, 2024.