United States. Bureau of Economic Analysis. "U.S. International Trade in Goods and Services: May 2014, BEA 14-32, CB 14-126, FT-900 (14-05)," Bureau of Economic Analysis (BEA) News Releases (July 3, 2014). https://fraser.stlouisfed.org/title/6148/item/602111, accessed on June 18, 2025.