Board of Governors of the Federal Reserve System (U.S.), 1935-. "Industry Subtotals and Individual Series, Seasonally Adjusted and Unadjusted," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "April 14, 1972," G.12.3 Industrial Production (1972-04-14) : 4-7. https://fraser.stlouisfed.org/title/55/item/59739/toc/469921 , accessed on May 4, 2024.