United States. Bureau of the Census. "Cover Page," in United States. Bureau of the Census. "September 1980," Business Conditions Digest (September 1980) : 1-1. https://fraser.stlouisfed.org/title/43/item/7409/toc/103029 , accessed on May 4, 2024.
United States. Bureau of the Census. "Cover Page," in United States. Bureau of the Census. "September 1980," Business Conditions Digest (September 1980) : 1-1. https://fraser.stlouisfed.org/title/43/item/7409/toc/103029 , accessed on May 4, 2024.