Gaya APA
Kotler, P., Armstrong, G. (2012).
Principles of marketing, 14th Ed. (14th. Ed.).
Singapore:
Pearson Education Int..
Gaya MLA
Kotler, Philip., Armstrong, Gary.
"Principles of marketing, 14th Ed.".
14th. Ed.
Singapore:
Pearson Education Int.,
2012.
Text.