MALTZ MAXWELL. (1998). ZERO - RESISTANCE SELLING. NEW PRENTICE HALL.
Lua i Stíl Chicago (17ú heag.)MALTZ MAXWELL. ZERO - RESISTANCE SELLING. NEW JERSEY: NEW PRENTICE HALL, 1998.
Lua MLA (9ú heag.)MALTZ MAXWELL. ZERO - RESISTANCE SELLING. NEW PRENTICE HALL, 1998.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.