United States. Bureau of the Census. "Composite Indexes," in United States. Bureau of the Census. "May 1970," Business Conditions Digest (May 1970) : 40-41. https://fraser.stlouisfed.org/title/43/item/7542/toc/272004 , accessed on May 9, 2024.
United States. Bureau of the Census. "Composite Indexes," in United States. Bureau of the Census. "May 1970," Business Conditions Digest (May 1970) : 40-41. https://fraser.stlouisfed.org/title/43/item/7542/toc/272004 , accessed on May 9, 2024.