United States. Bureau of Economic Analysis. "U.S. International Investment Position, Fourth Quarter and Year 2020 : Highlights: U.S. International Investment Position, Fourth Quarter 2020, BEA 21-15,"
Bureau of Economic Analysis (BEA) News Releases
(March 31, 2021).
https://fraser.stlouisfed.org/title/6148/item/601678/content/pdf/bea_newsreleases_20210331_highlights, accessed on July 9, 2025.