Terry, Morgan, author
Pearson, 2007
Buku Teks
Sellen, Derek
Hulton Educational Publications, 1982
Buku Teks
Smith, Mike (J. Mike), author
Oxford University Press, 1990
Buku Teks
John Flowerdew, Matthew Peacock
Cambridge University Press, 2001
Buku Teks
Callow, Margaret
Heinemann Educational Books, 1990
Buku Teks