United States. Bureau of Economic Analysis. "U.S. International Trade in Goods and Services: January 2019 : Highlights, Annual: 2018 Trade Gap is $622.1 Billion, BEA 19-10, CB 19-37," Bureau of Economic Analysis (BEA) News Releases (March 27, 2019). https://fraser.stlouisfed.org/title/6148/item/602784/content/pdf/bea_newsreleases_20190327_a_release-highlights-annual, accessed on March 26, 2025.