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. "March 1938," Federal Reserve Bulletin (March 1938) : 52-52. https://fraser.stlouisfed.org/title/62/item/20999/toc/338163 , accessed on April 26, 2024.