Thomas, Merlin, author
Penguin Books, 1985
Buku Referensi
Urwin, Kenneth, author
Langensheidt, 1988
Buku Referensi
Lambert, Rene, author
Ce?padues-Editions, 1991
Buku Referensi
edited by Grahame Johnston
Oxford University Press, 1980
Buku Referensi
Fowler, H. W. (Henry Watson), 1858-1933, author
At The Clarendon Press, 1954
Buku Teks