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. "June 1940," Federal Reserve Bulletin (June 1940) : 94-94. https://fraser.stlouisfed.org/title/62/item/21026/toc/357806 , accessed on April 23, 2024.