United States. Bureau of the Census. "Composite Indexes," in United States. Bureau of the Census. "June 1989," Business Conditions Digest (June 1989) : 68-68. https://fraser.stlouisfed.org/title/43/item/7514/toc/423573 , accessed on April 18, 2024.
United States. Bureau of the Census. "Composite Indexes," in United States. Bureau of the Census. "June 1989," Business Conditions Digest (June 1989) : 68-68. https://fraser.stlouisfed.org/title/43/item/7514/toc/423573 , accessed on April 18, 2024.