United States. Bureau of the Census. "Cover Page," in United States. Bureau of the Census. "September 1967," Business Conditions Digest (September 1967) : 1-1. https://fraser.stlouisfed.org/title/43/item/7243/toc/218174 , accessed on May 8, 2024.
United States. Bureau of the Census. "Cover Page," in United States. Bureau of the Census. "September 1967," Business Conditions Digest (September 1967) : 1-1. https://fraser.stlouisfed.org/title/43/item/7243/toc/218174 , accessed on May 8, 2024.