Hopkins, Diana
Cambridge grammar for ielts with answers: self-study grammar reference and practice
Cambridge University Press, 2011
 Buku Teks SO
Cullen, Pauline
Cambridge vocabulary for IELTS
Cambridge University Press, 2008
 Multimedia
Cambridge IELTS 6 : examination papers from University of Cambridge ESOL examinations
Cambridge University Press, 2007
 Multimedia
Cambridge IELTS 6 : examination papers from University of Cambridge ESOL examinations
Cambridge University Press, 2007
 Multimedia
Cambridge IELTS 7 : examination papers from University of Cambridge ESOL examinations
Cambridge University Press, 2009
 Multimedia