Boyd, H. W. (1989). Marketing research: Text and cases (7ª ed.). Irwin.
Lua i Stíl Chicago (17ú heag.)Boyd, Harper W. Marketing Research: Text and Cases. 7ª ed. Irwin, 1989.
Lua MLA (9ú heag.)Boyd, Harper W. Marketing Research: Text and Cases. 7ª ed. Irwin, 1989.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.