United States. Bureau of the Census. "Title Page," in United States. Bureau of the Census. "September 1970," Business Conditions Digest (September 1970) : 2-2. https://fraser.stlouisfed.org/title/43/item/7546/toc/75194 , accessed on March 28, 2024.
United States. Bureau of the Census. "Title Page," in United States. Bureau of the Census. "September 1970," Business Conditions Digest (September 1970) : 2-2. https://fraser.stlouisfed.org/title/43/item/7546/toc/75194 , accessed on March 28, 2024.