United States. Bureau of the Census. "NBER Short List," in United States. Bureau of the Census. "April 1970," Business Conditions Digest (April 1970) : 42-45. https://fraser.stlouisfed.org/title/43/item/7541/toc/179560 , accessed on April 24, 2024.
United States. Bureau of the Census. "NBER Short List," in United States. Bureau of the Census. "April 1970," Business Conditions Digest (April 1970) : 42-45. https://fraser.stlouisfed.org/title/43/item/7541/toc/179560 , accessed on April 24, 2024.