United States. Bureau of the Census. "Aggregate Series," in United States. Bureau of the Census. "August 1971," Business Conditions Digest (August 1971) : 46-48. https://fraser.stlouisfed.org/title/43/item/7557/toc/384914 , accessed on May 4, 2024.
United States. Bureau of the Census. "Aggregate Series," in United States. Bureau of the Census. "August 1971," Business Conditions Digest (August 1971) : 46-48. https://fraser.stlouisfed.org/title/43/item/7557/toc/384914 , accessed on May 4, 2024.