United States. Bureau of the Census. "Diffusion Indexes," in United States. Bureau of the Census. "August 1973," Business Conditions Digest (August 1973) : 52-53. https://fraser.stlouisfed.org/title/43/item/7324/toc/311005 , accessed on May 4, 2024.
United States. Bureau of the Census. "Diffusion Indexes," in United States. Bureau of the Census. "August 1973," Business Conditions Digest (August 1973) : 52-53. https://fraser.stlouisfed.org/title/43/item/7324/toc/311005 , accessed on May 4, 2024.