United States. Bureau of the Census. "Cyclical Indicators," in United States. Bureau of the Census. "May 1989," Business Conditions Digest (May 1989) : 14-16. https://fraser.stlouisfed.org/title/43/item/7513/toc/331681 , accessed on April 19, 2024.
United States. Bureau of the Census. "Cyclical Indicators," in United States. Bureau of the Census. "May 1989," Business Conditions Digest (May 1989) : 14-16. https://fraser.stlouisfed.org/title/43/item/7513/toc/331681 , accessed on April 19, 2024.