Kotler, P., & Armstrong, G. (1999). Principles of marketing (8th ed.). Prentice Hall.
Lua i Stíl Chicago (17ú heag.)Kotler, Philip, agus Gary Armstrong. Principles of Marketing. 8th ed. Upper Saddle River, NJ ; New Delhi: Prentice Hall, 1999.
Lua MLA (8ú heag.)Kotler, Philip, agus Gary Armstrong. Principles of Marketing. 8th ed. Prentice Hall, 1999.
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