United States. Bureau of Economic Analysis. "Gross Domestic Product: First Quarter 2018 (Third Estimate) | Corporate Profits: First Quarter 2018 (Revised Estimate), BEA 18-31," Bureau of Economic Analysis (BEA) News Releases (June 28, 2018). https://fraser.stlouisfed.org/title/6148/item/602639, accessed on September 18, 2024.