United States. Bureau of the Census. "Foreign Trade," in United States. Bureau of the Census. "August 1971," Business Conditions Digest (August 1971) : 19-19. https://fraser.stlouisfed.org/title/43/item/7557/toc/384901 , accessed on May 11, 2024.
United States. Bureau of the Census. "Foreign Trade," in United States. Bureau of the Census. "August 1971," Business Conditions Digest (August 1971) : 19-19. https://fraser.stlouisfed.org/title/43/item/7557/toc/384901 , accessed on May 11, 2024.