United States. Bureau of the Census. "September 1969," Business Conditions Digest (September 1969). https://fraser.stlouisfed.org/title/43/item/7534, accessed on July 11, 2024.
United States. Bureau of the Census. "September 1969," Business Conditions Digest (September 1969). https://fraser.stlouisfed.org/title/43/item/7534, accessed on July 11, 2024.