United States. Bureau of Economic Analysis. "Gross Domestic Product, Third Quarter 2018 (Second Estimate) | Corporate Profits, Third Quarter 2018 (Preliminary Estimate) : Historical Comparisons, BEA 18-64," Bureau of Economic Analysis (BEA) News Releases (November 28, 2018). https://fraser.stlouisfed.org/title/6148/item/602672/content/pdf/bea_newsreleases_20181128_historical-comparisons, accessed on March 26, 2025.