United States. Department of Commerce. "U.S. International Trade in Goods and Services, November 2011, BEA 12-01, CB 12-10, FT-900 (11-11),"
United States Department of Commerce News
(January 13, 2012).
https://fraser.stlouisfed.org/title/6148/item/601315, accessed on June 2, 2026.