Carter, Neil
Routledge, 1995
Buku Teks
Glendiining, J.W.
Charles Knight, 1973
Buku Teks
Lessem, Ronnie
Pustaka Binaman Pressindo , 1992
Buku Teks
Benney, Mark
Routledge and Kegan Paul, 1956
Buku Teks
Nicholson, T.A.J., author
Macmillan, 1978
Buku Teks