United States. Bureau of the Census. "Lagging Indicators," in United States. Bureau of the Census. "March 1968," Business Conditions Digest (March 1968) : 15-16. https://fraser.stlouisfed.org/title/43/item/7249/toc/113805 , accessed on May 5, 2024.
United States. Bureau of the Census. "Lagging Indicators," in United States. Bureau of the Census. "March 1968," Business Conditions Digest (March 1968) : 15-16. https://fraser.stlouisfed.org/title/43/item/7249/toc/113805 , accessed on May 5, 2024.