United States. Bureau of the Census. "Title Page," in United States. Bureau of the Census. "July 1971," Business Conditions Digest (July 1971) : 2-2. https://fraser.stlouisfed.org/title/43/item/7556/toc/149205 , accessed on May 11, 2024.
United States. Bureau of the Census. "Title Page," in United States. Bureau of the Census. "July 1971," Business Conditions Digest (July 1971) : 2-2. https://fraser.stlouisfed.org/title/43/item/7556/toc/149205 , accessed on May 11, 2024.