Gaya APA
Philip, K., Gary, A. (2013).
Principles of marketing Horizon Edition ( Fourteenth Edition ) (Ed.ke-14).
Harlow England:
Pearson Education Limited.
Gaya MLA
Kotler, Philip., Amstrong, Gary.
"Principles of marketing Horizon Edition ( Fourteenth Edition )".
Ed.ke-14
Harlow England:
Pearson Education Limited,
2013.
Textbook.