United States. Bureau of the Census. "Analytical Ratios," in United States. Bureau of the Census. "May 1970," Business Conditions Digest (May 1970) : 63-64. https://fraser.stlouisfed.org/title/43/item/7542/toc/272013 , accessed on May 1, 2024.
United States. Bureau of the Census. "Analytical Ratios," in United States. Bureau of the Census. "May 1970," Business Conditions Digest (May 1970) : 63-64. https://fraser.stlouisfed.org/title/43/item/7542/toc/272013 , accessed on May 1, 2024.