Gaya APA

Goeldner, C, R., Ritchie, J, R, B. (2011). Tourism: Principles, Practices, Philosophies (Ed. 12). : john Wiley and sons.

Gaya MLA

Goeldner, Charles, R.., Ritchie, J., R., Brent. "Tourism: Principles, Practices, Philosophies". Ed. 12 : john Wiley and sons, 2011. E-Book.