United States. Bureau of the Census. "May 1981," Business Conditions Digest (May 1981). https://fraser.stlouisfed.org/title/43/item/7417, accessed on April 26, 2024.
United States. Bureau of the Census. "May 1981," Business Conditions Digest (May 1981). https://fraser.stlouisfed.org/title/43/item/7417, accessed on April 26, 2024.