Gaya APA
Middleton, V, T. et al (2009).
Marketing in travel and tourism (4th ed.).
Amsterdam:
Elsevier-Butterworth Heinemann.
Gaya MLA
Middleton, Victor, T.C.. et al.
"Marketing in travel and tourism".
4th ed.
Amsterdam:
Elsevier-Butterworth Heinemann,
2009.
BUKU.