United States. Bureau of Economic Analysis. "U.S. International Trade in Goods and Services: July 2013 : Highlights: July 2013 Trade Gap is $39.1 Billion, BEA 13-40, CB 13-148, FT-900 (13-07),"
Bureau of Economic Analysis (BEA) News Releases
(September 4, 2013).
https://fraser.stlouisfed.org/title/6148/item/601563/content/pdf/bea_newsreleases_20130904_release-highlights, accessed on March 19, 2025.