U.S. International Trade in Goods and Services: March 2018 : Tables, BEA 18-21, CB 18-69
United States. Department of Commerce. "U.S. International Trade in Goods and Services: March 2018 : Tables, BEA 18-21, CB 18-69," United States Department of Commerce News (May 3, 2018). https://fraser.stlouisfed.org/title/6148/item/602628/content/xlsx/bea_newsreleases_20180503_tables-only, accessed on June 1, 2026.