United States. Bureau of Economic Analysis. "Gross Domestic Product: First Quarter 2009 (Preliminary)|Corporate Profits: First Quarter 2009 (Preliminary) : Technical Note, BEA 09-20," Bureau of Economic Analysis (BEA) News Releases (May 29, 2009). https://fraser.stlouisfed.org/title/6148/item/600670/content/pdf/bea_newsreleases_20090529_technical-note, accessed on March 20, 2025.