United States. Bureau of the Census. "Aggregate Series," in United States. Bureau of the Census. "July 1973," Business Conditions Digest (July 1973) : 49-51. https://fraser.stlouisfed.org/title/43/item/7323/toc/158484 , accessed on April 26, 2024.
United States. Bureau of the Census. "Aggregate Series," in United States. Bureau of the Census. "July 1973," Business Conditions Digest (July 1973) : 49-51. https://fraser.stlouisfed.org/title/43/item/7323/toc/158484 , accessed on April 26, 2024.