United States. Bureau of the Census. "Aggregate Series," in United States. Bureau of the Census. "June 1976," Business Conditions Digest (June 1976) : 50-51. https://fraser.stlouisfed.org/title/43/item/7358/toc/71619 , accessed on April 19, 2024.
United States. Bureau of the Census. "Aggregate Series," in United States. Bureau of the Census. "June 1976," Business Conditions Digest (June 1976) : 50-51. https://fraser.stlouisfed.org/title/43/item/7358/toc/71619 , accessed on April 19, 2024.