Coe, Graham
Routledge & Kegan Paul, 2005
Multimedia
Fitikides, T.J.
longmans, group limited, 1964
Buku Teks
Heinemann Educational Books, 1981
Buku Teks
Lucas, Michael
Heinemann Educational Books, 1981
Buku Teks
Howard, Godfrey, author
Pan Macmillan Publishers, 1993
Buku Referensi