United States. Bureau of Economic Analysis. "Gross Domestic Product: Second Quarter 2013 (Second Estimate) | Corporate Profits: Second Quarter 2013 (Preliminary Estimate) : Technical Note, BEA 13-38," Bureau of Economic Analysis (BEA) News Releases (August 29, 2013). https://fraser.stlouisfed.org/title/6148/item/601561/content/pdf/bea_newsreleases_20130829_technical-note, accessed on March 21, 2025.