Board of Governors of the Federal Reserve System (U.S.), 1935-. "Summary Groupings, Seasonally Adjusted," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "May 14, 1976," G.12.3 Industrial Production (1976-05-14) : 8-8. https://fraser.stlouisfed.org/title/55/item/59529/toc/470099 , accessed on May 1, 2024.