Morgan, D. L. (1993). Successful focus groups: Advancing the state of the art. Sage.
Dyfyniad Arddull ChicagoMorgan, David L. Successful Focus Groups: Advancing the State of the Art. Newbury Park, California: Sage, 1993.
Dyfyniad MLAMorgan, David L. Successful Focus Groups: Advancing the State of the Art. Sage, 1993.
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