United States. Bureau of the Census. "Composite Indexes," in United States. Bureau of the Census. "March 1971," Business Conditions Digest (March 1971) : 84-84. https://fraser.stlouisfed.org/title/43/item/7552/toc/289479 , accessed on May 8, 2024.
United States. Bureau of the Census. "Composite Indexes," in United States. Bureau of the Census. "March 1971," Business Conditions Digest (March 1971) : 84-84. https://fraser.stlouisfed.org/title/43/item/7552/toc/289479 , accessed on May 8, 2024.