Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "Zinc," in Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "June 1921," Federal Reserve Bulletin (June 1921) : 76-76. https://fraser.stlouisfed.org/title/62/item/20524/toc/363294 , accessed on April 19, 2024.