United States. Department of the Treasury. "Bill Tender, March 21, 1966, Release Number f-413," in United States. Department of the Treasury. "Volume 153," Press Releases of the United States Department of the Treasury (February 1, 1966 - March 30, 1966) : 691-707. https://fraser.stlouisfed.org/title/6111/item/586996/toc/539992 , accessed on June 24, 2024.