United States. Bureau of the Census. "Cover Page," in United States. Bureau of the Census. "April 1980," Business Conditions Digest (April 1980) : 1-1. https://fraser.stlouisfed.org/title/43/item/7404/toc/372937 , accessed on April 18, 2024.
United States. Bureau of the Census. "Cover Page," in United States. Bureau of the Census. "April 1980," Business Conditions Digest (April 1980) : 1-1. https://fraser.stlouisfed.org/title/43/item/7404/toc/372937 , accessed on April 18, 2024.