United States. Bureau of the Census. "Foreign Trade," in United States. Bureau of the Census. "March 1980," Business Conditions Digest (March 1980) : 88-88. https://fraser.stlouisfed.org/title/43/item/7402/toc/213905 , accessed on May 8, 2024.
United States. Bureau of the Census. "Foreign Trade," in United States. Bureau of the Census. "March 1980," Business Conditions Digest (March 1980) : 88-88. https://fraser.stlouisfed.org/title/43/item/7402/toc/213905 , accessed on May 8, 2024.