United States. Bureau of Economic Analysis. "Gross Domestic Product: Second Quarter 2013 (Second Estimate) | Corporate Profits: Second Quarter 2013 (Preliminary Estimate), BEA 13-38," Bureau of Economic Analysis (BEA) News Releases (August 29, 2013). https://fraser.stlouisfed.org/title/6148/item/601561, accessed on March 25, 2025.