United States. Bureau of Economic Analysis. "Gross Domestic Product: First Quarter 2018 (Advance Estimate) : Highlights: GDP Increases in First Quarter, BEA 18-19,"
Bureau of Economic Analysis (BEA) News Releases
(April 27, 2018).
https://fraser.stlouisfed.org/title/6148/item/602626/content/pdf/bea_newsreleases_20180427_release-highlights, accessed on March 15, 2025.