Schiffrin, Deborah, author
Blackwell publishing, 1994
Buku Teks
Schiffrin, Deborah, author
Cambridge University Press, 1996
Buku Teks
Blackwell , 2001
eBooks
Schiffrin, Deborah, author
Blackwell , 2000
Buku Teks
Nunan, David
Penguin English, 1993
Buku Teks