DUFFY PHILIP G. (1994). BUSINESS TO BUSINESS MARKETING. VISION BOOKS PVT. LTD.
Lua i Stíl Chicago (17ú heag.)DUFFY PHILIP G. BUSINESS TO BUSINESS MARKETING. NEW DELHI: VISION BOOKS PVT. LTD, 1994.
Lua MLA (9ú heag.)DUFFY PHILIP G. BUSINESS TO BUSINESS MARKETING. VISION BOOKS PVT. LTD, 1994.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.