United States. Bureau of the Census. "September 1978," Business Conditions Digest (September 1978). https://fraser.stlouisfed.org/title/43/item/7385, accessed on April 23, 2024.
United States. Bureau of the Census. "September 1978," Business Conditions Digest (September 1978). https://fraser.stlouisfed.org/title/43/item/7385, accessed on April 23, 2024.