United States. Bureau of the Census. "Method of Presentation," in United States. Bureau of the Census. "May 1971," Business Conditions Digest (May 1971) : 7-10. https://fraser.stlouisfed.org/title/43/item/7554/toc/129363 , accessed on July 8, 2024.
United States. Bureau of the Census. "Method of Presentation," in United States. Bureau of the Census. "May 1971," Business Conditions Digest (May 1971) : 7-10. https://fraser.stlouisfed.org/title/43/item/7554/toc/129363 , accessed on July 8, 2024.