Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "Market Groupings, Seasonally Adjusted," in Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "February 1967," Federal Reserve Bulletin (February 1967) : 110-110. https://fraser.stlouisfed.org/title/62/item/21386/toc/150176 , accessed on April 25, 2024.