Cooper, D. (2006). BUSINESS RESEARCH METHODS (9th.). McGraw Hill.
Lua i Stíl Chicago (17ú heag.)Cooper, Donald. BUSINESS RESEARCH METHODS. 9th. New Delhi: McGraw Hill, 2006.
Lua MLA (9ú heag.)Cooper, Donald. BUSINESS RESEARCH METHODS. 9th. McGraw Hill, 2006.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.