United States. Bureau of Economic Analysis. "Gross Domestic Product (Second Estimate), Corporate Profits (Preliminary Estimate), Third Quarter 2021 : Historical Comparisons, BEA 21-58," Bureau of Economic Analysis (BEA) News Releases (November 24, 2021). https://fraser.stlouisfed.org/title/6148/item/610124/content/pdf/bea_newsreleases_20211124a_historical, accessed on March 21, 2025.