United States. Bureau of the Census. "March 1980," Business Conditions Digest (March 1980). https://fraser.stlouisfed.org/title/43/item/7402, accessed on May 8, 2024.
United States. Bureau of the Census. "March 1980," Business Conditions Digest (March 1980). https://fraser.stlouisfed.org/title/43/item/7402, accessed on May 8, 2024.