United States. Bureau of the Census. "Cover Page," in United States. Bureau of the Census. "June 1987," Business Conditions Digest (June 1987) : 1-1. https://fraser.stlouisfed.org/title/43/item/7490/toc/321691 , accessed on May 7, 2024.
United States. Bureau of the Census. "Cover Page," in United States. Bureau of the Census. "June 1987," Business Conditions Digest (June 1987) : 1-1. https://fraser.stlouisfed.org/title/43/item/7490/toc/321691 , accessed on May 7, 2024.