United States. Bureau of the Census. "Analytical Ratios," in United States. Bureau of the Census. "March 1975," Business Conditions Digest (March 1975) : 68-68. https://fraser.stlouisfed.org/title/43/item/7343/toc/63831 , accessed on April 27, 2024.
United States. Bureau of the Census. "Analytical Ratios," in United States. Bureau of the Census. "March 1975," Business Conditions Digest (March 1975) : 68-68. https://fraser.stlouisfed.org/title/43/item/7343/toc/63831 , accessed on April 27, 2024.