United States. Department of the Treasury. "Withholding of appraisement on primary lead metal from Canada, July 26, 1973," in United States. Department of the Treasury. "Volume 185," Press Releases of the United States Department of the Treasury (July 2, 1973 - August 31, 1973) : 456-468. https://fraser.stlouisfed.org/title/6111/item/587028/toc/543350 , accessed on June 28, 2024.