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-. "September 15, 1989," G.12.3 Industrial Production (1989-09-15) : 20-20. https://fraser.stlouisfed.org/title/55/item/59752/toc/474611 , accessed on April 18, 2024.