White, Paul, editor
New Star Press, 2010
Buku Teks
Jiyuan, Tu, author
Elsevier, 2008
Buku Teks
Cunge, J.A., author
Pitman, 1980
Buku Teks
Norris, A.C., author
John Wiley & Sons, 1981
Buku Teks
Vogel, Arthur I., author
The English Language Book Society, 1966
Buku Teks