Allen, G.C.
Longmans, Green and Co., 1961
Buku Teks
Allen, G.C.
Oxford University Press, 1966
Buku Teks
Robson, R., author
Macmillan, 1957
Buku Teks
Grove, J.M.
Longmans, 1962
Buku Teks
edited by Tony Buxton, Paul Chapman and Paul Temple
Routledge , 1994
Buku Teks