United States. Bureau of the Census. "April 1969," Business Conditions Digest (April 1969). https://fraser.stlouisfed.org/title/43/item/7529, accessed on April 19, 2024.
United States. Bureau of the Census. "April 1969," Business Conditions Digest (April 1969). https://fraser.stlouisfed.org/title/43/item/7529, accessed on April 19, 2024.