United States. Bureau of Economic Analysis. "U.S. International Trade in Goods and Services, May 2009, BEA 09-32, CB 09-101, FT-900 (09-05),"
Bureau of Economic Analysis (BEA) News Releases
(July 10, 2009).
https://fraser.stlouisfed.org/title/6148/item/600681, accessed on July 11, 2025.