Rifki Feriandi, author
Peniti Media, 2014
Buku Teks
Olson, David R., author
Cambridge University Press , 1994
Buku Teks
Hyland, Ken, author
Longman, 2002
Buku Teks
Remy Sylado, author
Nuansa Cendekia, 2014
Buku Teks
Sharples, Mike, 1952-, author
Routledge, 1999
Buku Teks