United States. Bureau of the Census. "Method of Presentation," in United States. Bureau of the Census. "July 1969," Business Conditions Digest (July 1969) : 7-10. https://fraser.stlouisfed.org/title/43/item/7532/toc/358081 , accessed on May 8, 2024.
United States. Bureau of the Census. "Method of Presentation," in United States. Bureau of the Census. "July 1969," Business Conditions Digest (July 1969) : 7-10. https://fraser.stlouisfed.org/title/43/item/7532/toc/358081 , accessed on May 8, 2024.