Scales, Peter, 1949-, author
Open University Press, 2013
Buku Teks
Stevick, Earl W.
Cambridge University Press, 1982
Buku Teks
Collins, Janet, author
Routledge, 1997
Buku Teks
Brown, Douglas, author
Pearson Longman, 2007
Buku Teks
O`Shea, Tim, author
Harvester Press, 1983
Buku Teks