Fern, Edward F.
Advanced focus group research
Sage, 2001
 Buku Teks
Focus groups in social research
by Michael Bloor ... [et al.]
Sage, 2002
 Buku Teks
Morgan, David, L.
Basic and advanced focus groups
Sage, 2019
 Buku Teks
Marshall, Catherine
Designing qualitative research
Sage, 1999
 Buku Teks
Viswanathan, Madhu
Measurement error and research design
SAGE Publ., 2005
 Buku Teks