University of Cambridge. (2011). Cambridge preliminary English test 4 with answers: Examination papers from University of Cambridge ESOL examinations: English for Speakers of Other Languages. Việt Nam: Fahasa Printing Factory.

University of Cambridge. Cambridge Preliminary English Test 4 With Answers: Examination Papers From University of Cambridge ESOL Examinations: English for Speakers of Other Languages. Việt Nam: Fahasa Printing Factory, 2011.

University of Cambridge. Cambridge Preliminary English Test 4 With Answers: Examination Papers From University of Cambridge ESOL Examinations: English for Speakers of Other Languages. Việt Nam: Fahasa Printing Factory, 2011.