United States. Bureau of the Census. "Composite Indexes," in United States. Bureau of the Census. "March 1969," Business Conditions Digest (March 1969) : 83-83. https://fraser.stlouisfed.org/title/43/item/7528/toc/62165 , accessed on March 28, 2024.
United States. Bureau of the Census. "Composite Indexes," in United States. Bureau of the Census. "March 1969," Business Conditions Digest (March 1969) : 83-83. https://fraser.stlouisfed.org/title/43/item/7528/toc/62165 , accessed on March 28, 2024.