Greenbaum, T. L. (1993). The Handbook for Focus Group Research (Rev. ed.). Lexington Books An Imprint of Macmillan, Inc.
Lua i Stíl Chicago (17ú heag.)Greenbaum, Thomas L. The Handbook for Focus Group Research. Rev. ed. New York: Lexington Books An Imprint of Macmillan, Inc, 1993.
Lua MLA (9ú heag.)Greenbaum, Thomas L. The Handbook for Focus Group Research. Rev. ed. Lexington Books An Imprint of Macmillan, Inc, 1993.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.