Stevick, Earl W.
Cambridge Cambridge University Press 1991,
Buku Teks
Dörnyei, Zoltán
Cambridge University Press, 2004
Buku Teks
Morgan, John, 1944-2004
Cambridge University Press, 1983
Buku Teks
Allwright, Dick
Longman, 1993
Buku Teks
Robinson, W. Peter
Blackwell, 2003
Buku Teks