United States. Bureau of the Census. "Foreign Trade," in United States. Bureau of the Census. "December 1977," Business Conditions Digest (December 1977) : 51-51. https://fraser.stlouisfed.org/title/43/item/7376/toc/367986 , accessed on May 3, 2024.
United States. Bureau of the Census. "Foreign Trade," in United States. Bureau of the Census. "December 1977," Business Conditions Digest (December 1977) : 51-51. https://fraser.stlouisfed.org/title/43/item/7376/toc/367986 , accessed on May 3, 2024.