LEWIS, G. H. (1993). Direct Marketing Strategies And Lacties. Golden Books Centre.
Lua i Stíl Chicago (17ú heag.)LEWIS, Gordon Herschell. Direct Marketing Strategies And Lacties. Golden Books Centre, 1993.
Lua MLA (8ú heag.)LEWIS, Gordon Herschell. Direct Marketing Strategies And Lacties. Golden Books Centre, 1993.
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