United States. Bureau of the Census. "Cover Page," in United States. Bureau of the Census. "April 1975," Business Conditions Digest (April 1975) : 1-1. https://fraser.stlouisfed.org/title/43/item/7344/toc/176664 , accessed on July 17, 2024.
United States. Bureau of the Census. "Cover Page," in United States. Bureau of the Census. "April 1975," Business Conditions Digest (April 1975) : 1-1. https://fraser.stlouisfed.org/title/43/item/7344/toc/176664 , accessed on July 17, 2024.