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. "April 1951," Federal Reserve Bulletin (April 1951) : 80-80. https://fraser.stlouisfed.org/title/62/item/21196/toc/305526 , accessed on May 7, 2024.