United States. Bureau of Economic Analysis. "U.S. International Trade in Goods and Services: July 2013 : Full Release, 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, accessed on March 21, 2025.