Aaker, D. A. (2004). Marketing research ed.8. John Wiley & Sons.
Lua i Stíl Chicago (17ú heag.)Aaker, David A. Marketing Research Ed.8. John Wiley & Sons, 2004.
Lua MLA (8ú heag.)Aaker, David A. Marketing Research Ed.8. John Wiley & Sons, 2004.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.