Simeon, Richard
McGill Queen's University Press, 1977
Buku Teks
Park, William R., author
John Wiley & Sons, 1978
Buku Teks
Clarke, Philip, author
David & Charles, 1973
Buku Teks
Franklin, Benjamin, author
Pocket Books, 1948
Buku Teks
Llewellyn-Jones, Derek
Faber and Faber , 1983
Buku Teks