United States. Bureau of the Census. "Analytical Ratios," in United States. Bureau of the Census. "July 1970," Business Conditions Digest (July 1970) : 63-64. https://fraser.stlouisfed.org/title/43/item/7544/toc/187191 , accessed on May 3, 2024.
United States. Bureau of the Census. "Analytical Ratios," in United States. Bureau of the Census. "July 1970," Business Conditions Digest (July 1970) : 63-64. https://fraser.stlouisfed.org/title/43/item/7544/toc/187191 , accessed on May 3, 2024.