United States. Bureau of Economic Analysis. "National Income and Product Accounts : Technical Note (Release) : Gross Domestic Product: Second Quarter 2012 (Advance Estimate) | Revised Estimates: 2009 through First Quarter 2012, BEA 12-32," Bureau of Economic Analysis (BEA) News Releases (July 27, 2012). https://fraser.stlouisfed.org/title/6148/item/601345/content/pdf/bea_newsreleases_20120727_technical-note, accessed on March 26, 2025.