United States. Bureau of Economic Analysis. "Gross Domestic Product: Fourth and Annual Quarter 2010 (Second Estimate) : Technical Note, BEA 11-07," Bureau of Economic Analysis (BEA) News Releases (February 25, 2011). https://fraser.stlouisfed.org/title/6148/item/604066/content/pdf/bea_newsreleases_20110225_technical-note, accessed on March 22, 2025.