Greenbaum, T. L. (1993). The Handbook for Focus Group Research (Rev. ed.). Lexington Books An Imprint of Macmillan, Inc.
Dyfyniad Arddull ChicagoGreenbaum, Thomas L. The Handbook for Focus Group Research. Rev. ed. New York: Lexington Books An Imprint of Macmillan, Inc, 1993.
Dyfyniad MLAGreenbaum, Thomas L. The Handbook for Focus Group Research. Rev. ed. Lexington Books An Imprint of Macmillan, Inc, 1993.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.