Harold L. Vogel. (2012). Travel Industry Economics (2.). Cambridge University Press.
Chicago Style aipamenaHarold L. Vogel. Travel Industry Economics. 2. Cambridge University Press, 2012.
MLA aipamenaHarold L. Vogel. Travel Industry Economics. 2. Cambridge University Press, 2012.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.