United States. Department of the Treasury. "Lead and Zinc, January 14, 1965, Release Number d-1467," in United States. Department of the Treasury. "Volume 146," Press Releases of the United States Department of the Treasury (December 1, 1964 - February 1, 1965) : 327-329. https://fraser.stlouisfed.org/title/6111/item/586989/toc/539633 , accessed on June 24, 2024.