United States. Department of the Treasury. "Bill Offering, May 20, 1970," in United States. Department of the Treasury. "Volume 169," Press Releases of the United States Department of the Treasury (May 6, 1970 - August 3, 1970) : 212-214. https://fraser.stlouisfed.org/title/6111/item/587012/toc/541784 , accessed on June 16, 2024.