Long, Mike, author
Wiley Blackwell, 2015
Buku Teks
Nunan, David, author
Cambridge University Press, 2006
Buku Teks
Saville-Troike, Muriel, 1936-
Cambridge University Press, 2017
Buku Teks
Ellis, Rob, author
Blackwell, 1990
Buku Teks
Saville-Troike, Muriel, 1936-, author
Cambridge University Press , 2006
Buku Teks