Gillespie, Alexander
Oxford University press, 2014
Buku Teks
Donaldson, Thomas
Oxford University Press, 1989
Buku Teks
Blackwell, 2007
Buku Teks
edited by John Tingle and Alan Cribb
Blackwell, 2007
Buku Teks
Bickenbach, Jerome E., 1948-
Sage, 2012
Buku Teks