United States. Department of Commerce. "Real Direct Tourism Output Grew 0.8 Percent In Second Quarter 2007 : Full Release, BEA 07-44,"
United States Department of Commerce News
(September 24, 2007).
https://fraser.stlouisfed.org/title/6148/item/598985/content/pdf/bea_newsreleases_20070924_release, accessed on June 2, 2026.