United States. Bureau of Economic Analysis. "U.S. International Trade in Goods and Services: April 2018 : Highlights: April 2018 Trade Gap is $46.2 Billion, BEA 18-26, CB 18-81," Bureau of Economic Analysis (BEA) News Releases (June 6, 2018). https://fraser.stlouisfed.org/title/6148/item/602634/content/pdf/bea_newsreleases_20180606_release-highlights-monthly, accessed on March 15, 2025.