U.S. International Trade in Goods and Services: April 2018 : Tables, BEA 18-26, CB 18-81
United States. Department of Commerce. "U.S. International Trade in Goods and Services: April 2018 : Tables, BEA 18-26, CB 18-81," United States Department of Commerce News (June 6, 2018). https://fraser.stlouisfed.org/title/6148/item/602634/content/xlsx/bea_newsreleases_20180606_tables-only, accessed on June 12, 2026.