United States. Bureau of the Census. "Title Page," in United States. Bureau of the Census. "January 1971," Business Conditions Digest (January 1971) : 2-2. https://fraser.stlouisfed.org/title/43/item/7550/toc/171237 , accessed on April 23, 2024.
United States. Bureau of the Census. "Title Page," in United States. Bureau of the Census. "January 1971," Business Conditions Digest (January 1971) : 2-2. https://fraser.stlouisfed.org/title/43/item/7550/toc/171237 , accessed on April 23, 2024.