United States. Bureau of the Census. "September 1972," Business Conditions Digest (September 1972). https://fraser.stlouisfed.org/title/43/item/7313, accessed on March 19, 2024.
United States. Bureau of the Census. "September 1972," Business Conditions Digest (September 1972). https://fraser.stlouisfed.org/title/43/item/7313, accessed on March 19, 2024.