Gibbs, Graham R, author
Sage , 2013
Buku Teks
edited by Alan Bryman, Robert G. Burgess
Routledge , 1995
Buku Teks
Evanthia Lyons, Adrian Coyle
Sage, 2007
Buku Teks
Richard, Lyn, Author
Sage, 2014
Buku Teks
Silverman, David, author
SAGE Publ., 1993
Buku Teks