U.S. foreign trade:
General imports; world area by commodity groupings

APA Citation

United States. Bureau of the Census. Foreign Trade Division., United States. Bureau of the Census. U.S. foreign trade. [Washington]: U.S. Dept. of Commerce, Bureau of the Census.

MLA Citation

United States. Bureau of the Census. Foreign Trade Division, and United States. Bureau of the Census. U.S. Foreign Trade. [Washington]: U.S. Dept. of Commerce, Bureau of the Census,

Warning: These citations may not always be complete (especially for serials).