Ries, A. (1989). Bottom-up Marketing. McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)Ries, Al. Bottom-up Marketing. McGraw-Hill, 1989.
Lua MLA (8ú heag.)Ries, Al. Bottom-up Marketing. McGraw-Hill, 1989.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.