Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "Index of Production of Minerals, by Products," in Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "January 1930," Federal Reserve Bulletin (January 1930) : 20-20. https://fraser.stlouisfed.org/title/62/item/20697/toc/423292 , accessed on May 11, 2024.