United States. Bureau of the Census. "March 1987," Business Conditions Digest (March 1987). https://fraser.stlouisfed.org/title/43/item/7487, accessed on April 18, 2024.
United States. Bureau of the Census. "March 1987," Business Conditions Digest (March 1987). https://fraser.stlouisfed.org/title/43/item/7487, accessed on April 18, 2024.