Dyfyniad APA
Kotler, P., & Amstrong, G. (2013). Principles of marketing (14th ed.). Pearson educational limited.
Dyfyniad Arddull Chicago
Kotler, Philip, and Gary Amstrong. Principles of Marketing. 14th ed. England: Pearson educational limited, 2013.
Dyfyniad MLA
Kotler, Philip, and Gary Amstrong. Principles of Marketing. 14th ed. Pearson educational limited, 2013.
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