United States. Bureau of Economic Analysis. "Gross Domestic Product (Second Estimate), Corporate Profits (Preliminary Estimate), Second Quarter 2021 : Historical Comparisons, BEA 21-40," Bureau of Economic Analysis (BEA) News Releases (August 26, 2021). https://fraser.stlouisfed.org/title/6148/item/605027/content/pdf/bea_newsreleases_20210826_historical, accessed on March 23, 2025.