United States. Bureau of Economic Analysis. "U.S. International Trade in Goods and Services: June 2013 : Full Release, BEA 13-36, CB 13-139, FT-900 (13-06)," Bureau of Economic Analysis (BEA) News Releases (August 6, 2013). https://fraser.stlouisfed.org/title/6148/item/601559/content/pdf/bea_newsreleases_20130806, accessed on March 16, 2025.