Richmond, David, author
Macmillan, 1994
Buku Teks
Marett, Paul
Ashgate, 2002
Buku Teks
Paylor, Ian, author
Avebury, 1995
Buku Teks
Cowan, David, author
Cambridge University Press, 2011
Buku Teks
Redmond, Peter W. D., author
The M & E Handbook Series, 1993
Buku Teks