United States. Bureau of the Census. "Foreign Trade," in United States. Bureau of the Census. "August 1970," Business Conditions Digest (August 1970) : 73-73. https://fraser.stlouisfed.org/title/43/item/7545/toc/352946 , accessed on April 19, 2024.
United States. Bureau of the Census. "Foreign Trade," in United States. Bureau of the Census. "August 1970," Business Conditions Digest (August 1970) : 73-73. https://fraser.stlouisfed.org/title/43/item/7545/toc/352946 , accessed on April 19, 2024.