Proctor, T. (2005). Essentials of marketing research (4th ed.). Financial Times/Prentice Hall.
Lua i Stíl Chicago (17ú heag.)Proctor, Tony. Essentials of Marketing Research. 4th ed. Harlow, England ; New York: Financial Times/Prentice Hall, 2005.
Lua MLA (8ú heag.)Proctor, Tony. Essentials of Marketing Research. 4th ed. Financial Times/Prentice Hall, 2005.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.