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 1961," Federal Reserve Bulletin (February 1961) : 87-87. https://fraser.stlouisfed.org/title/62/item/21314/toc/151737 , accessed on April 17, 2024.