United States. Department of the Treasury. "Bill results on monthly bills, July 27, 1971," in United States. Department of the Treasury. "Volume 174," Press Releases of the United States Department of the Treasury (July 1, 1971 - August 31, 1971) : 190-191. https://fraser.stlouisfed.org/title/6111/item/587017/toc/542346 , accessed on June 25, 2024.