United States. Bureau of the Census. "Diffusion Indexes," in United States. Bureau of the Census. "June 1983," Business Conditions Digest (June 1983) : 80-83. https://fraser.stlouisfed.org/title/43/item/7442/toc/51365 , accessed on April 24, 2024.
United States. Bureau of the Census. "Diffusion Indexes," in United States. Bureau of the Census. "June 1983," Business Conditions Digest (June 1983) : 80-83. https://fraser.stlouisfed.org/title/43/item/7442/toc/51365 , accessed on April 24, 2024.