United States. Bureau of the Census. "Leading Indicators," in United States. Bureau of the Census. "June 1967," Business Conditions Digest (June 1967) : 37-41. https://fraser.stlouisfed.org/title/43/item/7240/toc/196637 , accessed on April 25, 2024.
United States. Bureau of the Census. "Leading Indicators," in United States. Bureau of the Census. "June 1967," Business Conditions Digest (June 1967) : 37-41. https://fraser.stlouisfed.org/title/43/item/7240/toc/196637 , accessed on April 25, 2024.