Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "Group Index Numbers - United States, Bureau of Labor Statistics," in Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "September 1923," Federal Reserve Bulletin (September 1923) : 57-57. https://fraser.stlouisfed.org/title/62/item/20552/toc/71806 , accessed on March 29, 2024.