United States. Department of the Treasury. "Preliminary figures on exchange of F and G Savings Bonds, December 6, 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) : 157-161. https://fraser.stlouisfed.org/title/6111/item/586966/toc/538333 , accessed on June 23, 2024.