United States. Bureau of the Census. "Analytical Ratios," in United States. Bureau of the Census. "August 1971," Business Conditions Digest (August 1971) : 63-64. https://fraser.stlouisfed.org/title/43/item/7557/toc/384921 , accessed on May 4, 2024.
United States. Bureau of the Census. "Analytical Ratios," in United States. Bureau of the Census. "August 1971," Business Conditions Digest (August 1971) : 63-64. https://fraser.stlouisfed.org/title/43/item/7557/toc/384921 , accessed on May 4, 2024.