Holbert, N. B. (1993). Practical Marketing Research. Prentice Hall.
Lua i Stíl Chicago (17ú heag.)Holbert, Neil B. Practical Marketing Research. Prentice Hall, 1993.
Lua MLA (8ú heag.)Holbert, Neil B. Practical Marketing Research. Prentice Hall, 1993.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.