Idea Books, 1997
Buku Referensi
Norden, Mary, author
Conran Octopus Limited, 2000
Buku Referensi
Graham, Bruce Desmond, author
Australian National University Press, 1966
Buku Teks
Guild Sourcebooks, 2000
Buku Referensi
Waller, Robert James, author
Warner Books, 1992
Buku Teks