United States. Department of the Treasury. "Bill Tender, March 10, 1969," in United States. Department of the Treasury. "Volume 164," Press Releases of the United States Department of the Treasury (January 22, 1969 - April 30, 1969) : 130-131. https://fraser.stlouisfed.org/title/6111/item/587007/toc/541343 , accessed on June 24, 2024.