United States. Department of the Treasury. "Final figures on 1 year 4% certificates, May 15, 1959," in United States. Department of the Treasury. "Volume 117," Press Releases of the United States Department of the Treasury (April 2, 1959 - June 30, 1959) : 169-172. https://fraser.stlouisfed.org/title/6111/item/586960/toc/537922 , accessed on June 25, 2024.