Simey, T.S., author
Clarendon Press, 1946
Buku Teks
Carrington, Selwyn H.H., author
Foris Publications, 1988
Buku Teks
Morris, Percy A.
Houghton Mifflin, 1975
Buku Referensi
John Doling, Roziah Omar
Ashgate, 2000
Buku Teks
Gilbert, Neil, author
Prentice-Hall, 1977
Buku Teks