Hewings, Martin, author
Cambridge University Press , 2004
Buku Teks
Sharples, Mike, 1952-, author
Routledge, 1999
Buku Teks
Sharples, Mike, 1952-, author
Ellis Horwood Limited, 1985
Buku Teks
Hickler, Holly
Allyn and Bacon, 1979
Buku Teks
Ur, Penny, author
Cambridge University Press, 1988
Buku Teks