Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "Factory Employment, by Industries (Adjusted for Seasonal Variation)," in Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "December 1940," Federal Reserve Bulletin (December 1940) : 66-67. https://fraser.stlouisfed.org/title/62/item/21032/toc/399543 , accessed on April 15, 2024.