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-. "January 14, 1969," G.12.3 Industrial Production (1969-01-14) : 3-3. https://fraser.stlouisfed.org/title/55/item/59546/toc/465855 , accessed on March 28, 2024.