Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "Freight-Car Loadings, by Classes," in Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "December 1931," Federal Reserve Bulletin (December 1931) : 19-19. https://fraser.stlouisfed.org/title/62/item/20719/toc/248113 , accessed on April 23, 2024.