Walker, David M.
Clarendon Press, 1980
Buku Referensi
Oxford Univesity Press, 2008
Buku Referensi
Johson, Bruce
Oxford University Press, 1987
Buku Teks
editor, Tom McArthur ; managing editor, Feri McArthur
Oxford University Press, 1992
Buku Referensi
edited by Margaret Drabble
Oxford University Press, 1985
Buku Referensi