Seltzer, Richard A., author
St. Martin's Press, 1996
Buku Teks
White, Patrick, 1971-, author
Palgrave Macmillan, 2009
Buku Teks
Egmose, Jonas, author
Routledge, 2015
Buku Teks
Robson, Colin, author
Oxford, 2002
Buku Teks
May, Tim, author
Open University Press, 2001
Buku Teks