United States. Bureau of Economic Analysis. "Gross Domestic Product: Fourth Quarter and Annual 2013 (Advance Estimate) : Technical Note, BEA 14-03," Bureau of Economic Analysis (BEA) News Releases (January 30, 2014). https://fraser.stlouisfed.org/title/6148/item/602083/content/pdf/bea_newsreleases_20140130_technical-note, accessed on March 17, 2025.