United States. President and Council of Economic Advisers (U.S.). "Indexes of Output per Man-hour and Related Data," in United States. President and Council of Economic Advisers (U.S.). "1964," Economic Report of the President (1964) : 253-253. https://fraser.stlouisfed.org/title/45/item/8135/toc/269283 , accessed on April 24, 2024.