United States. Bureau of Economic Analysis. "Total Tourism-Related Sales Top $1 Trillion Mark : Total Tourism-Related Employment Up 0.8 Percent in First Quarter, BEA 05-39," Bureau of Economic Analysis (BEA) News Releases (September 8, 2005). https://fraser.stlouisfed.org/title/6148/item/597994, accessed on March 21, 2025.