United States. Bureau of the Census. "NBER Short List," in United States. Bureau of the Census. "July 1969," Business Conditions Digest (July 1969) : 42-45. https://fraser.stlouisfed.org/title/43/item/7532/toc/358102 , accessed on May 4, 2024.
United States. Bureau of the Census. "NBER Short List," in United States. Bureau of the Census. "July 1969," Business Conditions Digest (July 1969) : 42-45. https://fraser.stlouisfed.org/title/43/item/7532/toc/358102 , accessed on May 4, 2024.