United States. Bureau of the Census. "Title Page," in United States. Bureau of the Census. "December 1987," Business Conditions Digest (December 1987) : 2-2. https://fraser.stlouisfed.org/title/43/item/7496/toc/189528 , accessed on April 25, 2024.
United States. Bureau of the Census. "Title Page," in United States. Bureau of the Census. "December 1987," Business Conditions Digest (December 1987) : 2-2. https://fraser.stlouisfed.org/title/43/item/7496/toc/189528 , accessed on April 25, 2024.