Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "Indexes of Freight-Car Loadings, by Classes," in Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "June 1937," Federal Reserve Bulletin (June 1937) : 24-27. https://fraser.stlouisfed.org/title/62/item/20743/toc/302973 , accessed on May 11, 2024.