United States. Department of Commerce. "Gross Domestic Product: Second Quarter 2018 (Third Estimate) | Corporate Profits: Second Quarter 2018 (Revised Estimate), BEA 18-51,"
United States Department of Commerce News
(September 27, 2018).
https://fraser.stlouisfed.org/title/6148/item/602659, accessed on June 1, 2026.