United States. Bureau of the Census. "Analytical Measures," in United States. Bureau of the Census. "May 1973," Business Conditions Digest (May 1973) : 14-14. https://fraser.stlouisfed.org/title/43/item/7321/toc/34323 , accessed on May 1, 2024.
United States. Bureau of the Census. "Analytical Measures," in United States. Bureau of the Census. "May 1973," Business Conditions Digest (May 1973) : 14-14. https://fraser.stlouisfed.org/title/43/item/7321/toc/34323 , accessed on May 1, 2024.