Ferrell, O. C. (2002). Marketing Strategy Second Edition/O. C. Ferrel. South-Western.
Lua i Stíl Chicago (17ú heag.)Ferrell, O. C. Marketing Strategy Second Edition/O. C. Ferrel. South-Western, 2002.
Lua MLA (8ú heag.)Ferrell, O. C. Marketing Strategy Second Edition/O. C. Ferrel. South-Western, 2002.
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