United States. Department of the Treasury. "Bill tender on 237-day bills, August 15, 1957," in United States. Department of the Treasury. "Volume 111," Press Releases of the United States Department of the Treasury (July 30, 1957 - December 30, 1957) : 55-58. https://fraser.stlouisfed.org/title/6111/item/586954/toc/537444 , accessed on June 25, 2024.