Clinton, Michael
Sydney Prentice Hall 1996 ,
Buku Teks
[edited by] Katherine M. Fortinash, Patricia A. Holoday Worret
St Louis , 2004
Buku Teks
Cook, J. Sue
Addison Wesley Publishing, 1987
Buku Teks
Fontaine, Karen Lee, author
Pearson Education, 2003
Multimedia
Rinomhota, A. Shupikai, author
Churchill Living Stone, 2000
Buku Teks