United States. Department of Commerce. "U.S. International Trade in Goods and Services, October 2011, BEA 11-57, CB 11-210, FT-900 (11-10),"
United States Department of Commerce News
(December 9, 2011).
https://fraser.stlouisfed.org/title/6148/item/604117, accessed on June 13, 2026.