United States. Department of the Treasury. "Bill Tender, December 20, 1960," in United States. Department of the Treasury. "Volume 123," Press Releases of the United States Department of the Treasury (October 4, 1960 - January 18, 1961) : 107-110. https://fraser.stlouisfed.org/title/6111/item/586966/toc/538319 , accessed on June 23, 2024.