Cornerstone ceremony for new Philadelphia Mint set for September 18, 1968, September 15, 1968, Release Number f-1348
United States. Department of the Treasury. "Cornerstone ceremony for new Philadelphia Mint set for September 18, 1968, September 15, 1968, Release Number f-1348," in United States. Department of the Treasury. "Volume 162," Press Releases of the United States Department of the Treasury (June 5, 1968 - September 30, 1968) : 528-529. https://fraser.stlouisfed.org/title/6111/item/587005/toc/541152 , accessed on June 18, 2024.