Ferrel, O. (2014). Marketing Strategy Text and cases (6th edition). Cengage Lerning.
Lua i Stíl Chicago (17ú heag.)Ferrel, O.C. Marketing Strategy Text and Cases (6th Edition). Cengage Lerning, 2014.
Lua MLA (8ú heag.)Ferrel, O.C. Marketing Strategy Text and Cases (6th Edition). Cengage Lerning, 2014.
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