United States. Bureau of the Census. "Analytical Ratios," in United States. Bureau of the Census. "May 1970," Business Conditions Digest (May 1970) : 94-94. https://fraser.stlouisfed.org/title/43/item/7542/toc/272043 , accessed on March 28, 2024.
United States. Bureau of the Census. "Analytical Ratios," in United States. Bureau of the Census. "May 1970," Business Conditions Digest (May 1970) : 94-94. https://fraser.stlouisfed.org/title/43/item/7542/toc/272043 , accessed on March 28, 2024.