Lockwood, A., & Medlik, S. (2002). Tourism and hospitality in the 21st century. Butterworth-Heinemann.
Lua i Stíl Chicago (17ú heag.)Lockwood, A., agus S. Medlik. Tourism and Hospitality in the 21st Century. Oxford: Butterworth-Heinemann, 2002.
Lua MLA (9ú heag.)Lockwood, A., agus S. Medlik. Tourism and Hospitality in the 21st Century. Butterworth-Heinemann, 2002.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.