Board of Governors of the Federal Reserve System (U.S.), 1935-. "Explanatory Note," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "December 15, 1989," G.12.3 Industrial Production (1989-12-15) : 20-20. https://fraser.stlouisfed.org/title/55/item/59755/toc/474672 , accessed on April 27, 2024.