United States. Bureau of the Census. "Cover Page," in United States. Bureau of the Census. "July 1987," Business Conditions Digest (July 1987) : 1-1. https://fraser.stlouisfed.org/title/43/item/7491/toc/293367 , accessed on March 18, 2024.
United States. Bureau of the Census. "Cover Page," in United States. Bureau of the Census. "July 1987," Business Conditions Digest (July 1987) : 1-1. https://fraser.stlouisfed.org/title/43/item/7491/toc/293367 , accessed on March 18, 2024.