United States. Department of Commerce. "U.S. International Trade in Goods and Services: July 2006, CB 06-139, BEA 06-39, FT-900 (06-07),"
United States Department of Commerce News
(September 12, 2006).
https://fraser.stlouisfed.org/title/6148/item/598047, accessed on June 1, 2026.