Gorton, K. (1983). Low-cost marketing research: A guide for small businesses. Wiley.
Lua i Stíl Chicago (17ú heag.)Gorton, Keith. Low-cost Marketing Research: A Guide for Small Businesses. Chichester: Wiley, 1983.
Lua MLA (9ú heag.)Gorton, Keith. Low-cost Marketing Research: A Guide for Small Businesses. Wiley, 1983.
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