Tapp, A. (2012). Principles of Direct and Database Marketing (4th.). Pearson.
Lua i Stíl Chicago (17ú heag.)Tapp, Alan. Principles of Direct and Database Marketing. 4th. Pearson, 2012.
Lua MLA (9ú heag.)Tapp, Alan. Principles of Direct and Database Marketing. 4th. Pearson, 2012.
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