Hudman, L. E., & Jackson, R. H. (2003). Geography of travel & tourism (4th ed.). Thomson/Delmar Learning.
Lua i Stíl Chicago (17ú heag.)Hudman, Lloyd E., agus Richard H. Jackson. Geography of Travel & Tourism. 4th ed. Clifton Park, NY: Thomson/Delmar Learning, 2003.
Lua MLA (9ú heag.)Hudman, Lloyd E., agus Richard H. Jackson. Geography of Travel & Tourism. 4th ed. Thomson/Delmar Learning, 2003.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.