United States. Bureau of the Census. "Title Page," in United States. Bureau of the Census. "December 1969," Business Conditions Digest (December 1969) : 2-2. https://fraser.stlouisfed.org/title/43/item/7537/toc/83530 , accessed on April 18, 2024.
United States. Bureau of the Census. "Title Page," in United States. Bureau of the Census. "December 1969," Business Conditions Digest (December 1969) : 2-2. https://fraser.stlouisfed.org/title/43/item/7537/toc/83530 , accessed on April 18, 2024.