Gaya APA
Ritchie, J, B., Goeldner, C, R. (2012).
Tourism Principles, Practices, Philosophies (12th Ed.).
Hoboken, NJ.:
John Wiley and Sons, Inc..
Gaya MLA
Ritchie, J.R., Brent., Goeldner, Charles, R..
"Tourism Principles, Practices, Philosophies".
12th Ed.
Hoboken, NJ.:
John Wiley and Sons, Inc.,
2012.
BUKU.