United States. Bureau of the Census. "Foreign Trade (chart)," in United States. Bureau of the Census. "May 1988," Business Conditions Digest (May 1988) : 50-50. https://fraser.stlouisfed.org/title/43/item/7501/toc/40631 , accessed on May 3, 2024.
United States. Bureau of the Census. "Foreign Trade (chart)," in United States. Bureau of the Census. "May 1988," Business Conditions Digest (May 1988) : 50-50. https://fraser.stlouisfed.org/title/43/item/7501/toc/40631 , accessed on May 3, 2024.