United States. Bureau of the Census. "Analytical Ratios," in United States. Bureau of the Census. "June 1975," Business Conditions Digest (June 1975) : 72-72. https://fraser.stlouisfed.org/title/43/item/7346/toc/263748 , accessed on April 20, 2024.
United States. Bureau of the Census. "Analytical Ratios," in United States. Bureau of the Census. "June 1975," Business Conditions Digest (June 1975) : 72-72. https://fraser.stlouisfed.org/title/43/item/7346/toc/263748 , accessed on April 20, 2024.