United States. President and Council of Economic Advisers (U.S.). "Indexes of Output per Man-hour and Related Data, Private Economy," in United States. President and Council of Economic Advisers (U.S.). "1967," Economic Report of the President (1967) : 255-255. https://fraser.stlouisfed.org/title/45/item/8138/toc/257172 , accessed on April 19, 2024.