Bloomsbury Publishing Limited, 1993
Buku Referensi
Burton, William C., author
New York : Macmillan, 1992,
Buku Referensi
Chambers, 1994
Buku Referensi
edited by Susan M. Lloyd
Penguin Books, [date of publication not identified]
Buku Referensi
Penguin Books, 1987
Buku Referensi