United States. Bureau of the Census. "Diffusion Indexes," in United States. Bureau of the Census. "May 1983," Business Conditions Digest (May 1983) : 80-83. https://fraser.stlouisfed.org/title/43/item/7441/toc/182741 , accessed on May 9, 2024.
United States. Bureau of the Census. "Diffusion Indexes," in United States. Bureau of the Census. "May 1983," Business Conditions Digest (May 1983) : 80-83. https://fraser.stlouisfed.org/title/43/item/7441/toc/182741 , accessed on May 9, 2024.