Board of Governors of the Federal Reserve System (U.S.), 1935-. "Industry Groupings, Seasonally Adjusted," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "June 16, 1969," G.12.3 Industrial Production (1969-06-16) : 3-3. https://fraser.stlouisfed.org/title/55/item/59554/toc/465879 , accessed on April 23, 2024.