Rinvolucri, Mario, author
Cambridge University Press, 2006
Buku Teks
Greenbaum, Sidney
Longman , 1990
Buku Teks
Macdonell, Arthur Anthony, 1854-1930, author
Oxford University Press, 1927
Buku Teks
Watcyn-Jones, Peter
Penguin books, 1995
Buku Teks
Ur, Penny, author
Cambridge University Press, 1988
Buku Teks