Keylor, William R., 1944-, author
Oxford University Press, 1996
Buku Teks
Teed, Peter, author
Oxford University Press , 1992
Buku Referensi
editor, Cameron Hazlehurst
Australian National University Press, 1979
Buku Teks
Gilbert, Martin
Avon books, 1997
Buku Teks
Mair, Christian, author
Cambridge University Press, 2006
Buku Teks