United States. Bureau of the Census. "Other Key Indicators," in United States. Bureau of the Census. "July 1975," Business Conditions Digest (July 1975) : 58-70. https://fraser.stlouisfed.org/title/43/item/7347/toc/239364 , accessed on May 8, 2024.
United States. Bureau of the Census. "Other Key Indicators," in United States. Bureau of the Census. "July 1975," Business Conditions Digest (July 1975) : 58-70. https://fraser.stlouisfed.org/title/43/item/7347/toc/239364 , accessed on May 8, 2024.