Technical Paper - The 1961-69 Economic Expansion in the United States: The Statistical Record
United States. Bureau of the Census. "Technical Paper - The 1961-69 Economic Expansion in the United States: The Statistical Record," in United States. Bureau of the Census. "January 1970," Business Conditions Digest (January 1970) : 107-118. https://fraser.stlouisfed.org/title/43/item/7538/toc/341804 , accessed on May 1, 2024.