United States. Bureau of the Census. "Title Page," in United States. Bureau of the Census. "April 1967," Business Conditions Digest (April 1967) : 2-2. https://fraser.stlouisfed.org/title/43/item/7238/toc/360825 , accessed on April 25, 2024.
United States. Bureau of the Census. "Title Page," in United States. Bureau of the Census. "April 1967," Business Conditions Digest (April 1967) : 2-2. https://fraser.stlouisfed.org/title/43/item/7238/toc/360825 , accessed on April 25, 2024.