United States. Bureau of Economic Analysis. "Private Services-Producing Sector Continued to Lead Growth in 2006 : Highlights: Private Services Leads Real Growth in 2006 : Revised Statistics of Gross Domestic Product by Industry, 2004-2006, BEA 08-02,"
Bureau of Economic Analysis (BEA) News Releases
(January 29, 2008).
https://fraser.stlouisfed.org/title/6148/item/600435/content/pdf/bea_newsreleases_20080129_highlights, accessed on July 12, 2025.