United States. Bureau of the Census. "Composite Indexes," in United States. Bureau of the Census. "May 1988," Business Conditions Digest (May 1988) : 16-17. https://fraser.stlouisfed.org/title/43/item/7501/toc/40614 , accessed on March 29, 2024.
United States. Bureau of the Census. "Composite Indexes," in United States. Bureau of the Census. "May 1988," Business Conditions Digest (May 1988) : 16-17. https://fraser.stlouisfed.org/title/43/item/7501/toc/40614 , accessed on March 29, 2024.