Cambridge English language assessment. (2017). Cambridge English IELTS 9 with answers: Authentic examination papers from Cambridge Esol. England: Cambridge University press.
Trích dẫn kiểu ChicagoCambridge English language assessment. Cambridge English IELTS 9 With Answers: Authentic Examination Papers From Cambridge Esol. England: Cambridge University press, 2017.
MLA引文Cambridge English language assessment. Cambridge English IELTS 9 With Answers: Authentic Examination Papers From Cambridge Esol. England: Cambridge University press, 2017.
警告：这些引文格式不一定是100％准确.