United States. Department of the Treasury. "Weekly Bill Results, December 21, 1973," in United States. Department of the Treasury. "Volume 187," Press Releases of the United States Department of the Treasury (November 6, 1973 - December 28, 1973) : 720-720. https://fraser.stlouisfed.org/title/6111/item/587030/toc/543581 , accessed on June 3, 2024.