Finn, Paul, author
Oxford University Press, 1987
Buku Referensi
Vermeesch, R.B., author
Butterworth, 1995
Buku Teks
Nightingale, Kath, author
Prentice-Hall, 2002
Buku Teks
edited by Emile Woolf
Pitman, 1986
Buku Teks
Chicago, Ill. Commerce Clearing House 1966,
Buku Teks