"Technical Information About the BLS Multifactor Productivity Measures," U. S. Bureau of Labor Statistics, September 26, 2007, .

Raymond W. Goldsmith, "The Growth of Reproducible Wealth of the United States of America from 1805 to 1950," in International Association for Research in Income and Wealth, Income and Wealth of the United States: Trends and Structure, Income and Wealth Series II (Bowes and Bowes, 1952), 306; Raymond W. Goldsmith, The National Wealth of the United States in the Postwar Period (Princeton, NJ: Princeton University Press, 1962), appendix A and B.