United States. Bureau of the Census. "Aggregate Series," in United States. Bureau of the Census. "July 1969," Business Conditions Digest (July 1969) : 46-48. https://fraser.stlouisfed.org/title/43/item/7532/toc/358103 , accessed on March 29, 2024.
United States. Bureau of the Census. "Aggregate Series," in United States. Bureau of the Census. "July 1969," Business Conditions Digest (July 1969) : 46-48. https://fraser.stlouisfed.org/title/43/item/7532/toc/358103 , accessed on March 29, 2024.