United States. Bureau of Economic Analysis. "U.S. International Trade in Goods and Services, March 2021 : Highlights: March 2021 Trade Gap Is $74.4 Billion, BEA 21-20, CB 21-67," Bureau of Economic Analysis (BEA) News Releases (May 4, 2021). https://fraser.stlouisfed.org/title/6148/item/602552/content/pdf/bea_newsreleases_20210504_highlights, accessed on March 24, 2025.