Donnelly, Daniel
Rockport Publishers, 2011
Multimedia
Hewes ,Rachel
Rockport Publishers, 2010
Buku Referensi
Dabner, David
Page One, 2006
Buku Teks
Heskett, John
Oxford University Press, 2002
Buku Teks
Gwon, Young-Soo
Dnbooks publishing company, 2008
Multimedia