United States. Bureau of the Census. "Analytical Ratios," in United States. Bureau of the Census. "July 1975," Business Conditions Digest (July 1975) : 72-72. https://fraser.stlouisfed.org/title/43/item/7347/toc/239373 , accessed on May 11, 2024.
United States. Bureau of the Census. "Analytical Ratios," in United States. Bureau of the Census. "July 1975," Business Conditions Digest (July 1975) : 72-72. https://fraser.stlouisfed.org/title/43/item/7347/toc/239373 , accessed on May 11, 2024.