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. "September 1939," Federal Reserve Bulletin (September 1939) : 106-106. https://fraser.stlouisfed.org/title/62/item/21017/toc/349515 , accessed on May 4, 2024.