United States. Bureau of Economic Analysis. "Gross Domestic Product: Fourth Quarter and Annual 2011 (Advance Estimate) : Full Release, BEA 12-02,"
Bureau of Economic Analysis (BEA) News Releases
(January 27, 2012).
https://fraser.stlouisfed.org/title/6148/item/601316/content/pdf/bea_newsreleases_20120127, accessed on June 12, 2025.