United States. Department of the Treasury. "Lead and Zinc, July 13, 1962, Release Number d-542," in United States. Department of the Treasury. "Volume 133," Press Releases of the United States Department of the Treasury (July 2, 1962 - September 30, 1962) : 93-96. https://fraser.stlouisfed.org/title/6111/item/586976/toc/538860 , accessed on June 24, 2024.