United States. Bureau of Economic Analysis. "Gross Domestic Product: Fouth Quarter and Annual 2010 (Advance Estimate) : Technical Note, BEA 11-02," Bureau of Economic Analysis (BEA) News Releases (January 28, 2011). https://fraser.stlouisfed.org/title/6148/item/604062/content/pdf/bea_newsreleases_20110128_technical-note, accessed on March 21, 2025.