Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "Industrial Production - Indexes and Gross Value," in Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "February 1981," Federal Reserve Bulletin (February 1981) : 136-137. https://fraser.stlouisfed.org/title/62/item/20474/toc/117791 , accessed on December 11, 2023.