United States. Bureau of the Census. "Composite Indexes," in United States. Bureau of the Census. "June 1987," Business Conditions Digest (June 1987) : 66-66. https://fraser.stlouisfed.org/title/43/item/7490/toc/321725 , accessed on April 19, 2024.
United States. Bureau of the Census. "Composite Indexes," in United States. Bureau of the Census. "June 1987," Business Conditions Digest (June 1987) : 66-66. https://fraser.stlouisfed.org/title/43/item/7490/toc/321725 , accessed on April 19, 2024.