APA

United States, . (19901996). U.S. merchandise trade: exports, general imports, and imports for consumption. Washington D.C: U.S. Dept. of Commerce, Bureau of the Census.

Chicago

United States, . 19901996. U.S. merchandise trade: exports, general imports, and imports for consumption. Washington D.C: U.S. Dept. of Commerce, Bureau of the Census.

Harvard

United States, . (19901996). U.S. merchandise trade: exports, general imports, and imports for consumption. Washington D.C: U.S. Dept. of Commerce, Bureau of the Census.

MLA

United States, . U.S. merchandise trade: exports, general imports, and imports for consumption. Washington D.C: U.S. Dept. of Commerce, Bureau of the Census. 19901996.