United States. Bureau of the Census. "Diffusion Indexes," in United States. Bureau of the Census. "July 1976," Business Conditions Digest (July 1976) : 52-53. https://fraser.stlouisfed.org/title/43/item/7359/toc/244121 , accessed on May 9, 2024.
United States. Bureau of the Census. "Diffusion Indexes," in United States. Bureau of the Census. "July 1976," Business Conditions Digest (July 1976) : 52-53. https://fraser.stlouisfed.org/title/43/item/7359/toc/244121 , accessed on May 9, 2024.