Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "Industrial Production, by Industries (Unadjusted Indexes)," in Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "February 1939," Federal Reserve Bulletin (February 1939) : 52-52. https://fraser.stlouisfed.org/title/62/item/21010/toc/154651 , accessed on May 3, 2024.