Etzel, M. J. (2007). Marketing (14th ed.). McGraw-Hill/Irwin.
Lua i Stíl Chicago (17ú heag.)Etzel, Michael J. Marketing. 14th ed. Boston ; New Delhi: McGraw-Hill/Irwin, 2007.
Lua MLA (8ú heag.)Etzel, Michael J. Marketing. 14th ed. McGraw-Hill/Irwin, 2007.
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