Examination papers from University of Cambridge ESOL Examinations: English for speakers of other langusges. (2007). Cambridge Preliminary English test 4 with answers. New York: Cambridge university press.
Trích dẫn kiểu ChicagoExamination papers from University of Cambridge ESOL Examinations: English for speakers of other langusges. Cambridge Preliminary English Test 4 With Answers. New York: Cambridge university press, 2007.
Trích dẫn MLAExamination papers from University of Cambridge ESOL Examinations: English for speakers of other langusges. Cambridge Preliminary English Test 4 With Answers. New York: Cambridge university press, 2007.
Cảnh báo: Các trích dẫn này có thể không phải lúc nào cũng chính xác 100%.