Stevick, Earl W.
Cambridge Cambridge University Press 1991,
Buku Teks
Dörnyei, Zoltán, author
Cambridge University Press, 2004
Buku Teks
edited by Albert H. Marckwardt
National Council of Teachers of English, 1968
Buku Teks
Richards, Jack C., author
Cambridge University Press, 2006
Buku Teks
Richards, Jack C., author
Cambridge University Press, 1994
Buku Teks