DOUGLAS, S. P. (1983). International Marketing Research / Susan P. Douglas And C. Samuel Craig. Prentice Hall.
Lua i Stíl Chicago (17ú heag.)DOUGLAS, Susan P. International Marketing Research / Susan P. Douglas And C. Samuel Craig. Prentice Hall, 1983.
Lua MLA (8ú heag.)DOUGLAS, Susan P. International Marketing Research / Susan P. Douglas And C. Samuel Craig. Prentice Hall, 1983.
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