MCDONALD WILLIAM J. (1998). DIRECT MARKETING: AN INTEGRATED APPROACH. IRWIN MCGRAW-HILL.
Lua i Stíl Chicago (17ú heag.)MCDONALD WILLIAM J. DIRECT MARKETING: AN INTEGRATED APPROACH. BOSTON: IRWIN MCGRAW-HILL, 1998.
Lua MLA (9ú heag.)MCDONALD WILLIAM J. DIRECT MARKETING: AN INTEGRATED APPROACH. IRWIN MCGRAW-HILL, 1998.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.