Cook, R. A., Yale, L. J., & Marqua, J. J. (1999). Tourism: The business of travel. Upper Saddle River, N.J: Prentice Hall.
Chicago Style aipamenaCook, Roy A., Laura J. Yale, và Joseph J. Marqua. Tourism: The Business of Travel. Upper Saddle River, N.J: Prentice Hall, 1999.
MLA aipamenaCook, Roy A., Laura J. Yale, và Joseph J. Marqua. Tourism: The Business of Travel. Upper Saddle River, N.J: Prentice Hall, 1999.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.